Article

Host specificity, infrequent major host switching and the diversification of highly host-specific symbionts: The case of vane-dwelling feather mites

Global Ecology and Biogeography

November 2017
27(2)

DOI:10.1111/geb.12680

Authors:

Jorge Doña

University of Granada

Sergey V. Mironov

Russian Academy of Sciences

David Serrano

Spanish National Research Council

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Aim Highly host‐specific symbionts are very rarely found except with their typical host species. Although switches to new hosts are rare and difficult to detect, a switch to a host phylogenetically distant from the original one (a ‘major host switch’) could allow diversification of the symbionts onto the new host lineage. The consequences of such major host switches on the diversification of highly host‐specific symbionts of animals have rarely been explored. Here, we examine the host specificity of vane‐dwelling feather mites, a group that shows strong specificity, together with their host‐switching dynamics and the consequences of major host switches for their diversification. Location Global. Time period From 1882 to 2015. Major taxa studied Feather mites and birds. Methods Using the largest published dataset of feather mite–bird associations, we analysed raw, phylogenetic and geographical host specificity of feather mites. We studied host‐switching dynamics by describing the sharing by feather mites of bird species with different phylogenetic distances. For three of the most species‐rich feather mite families, we quantified the consequences of major host switches for feather mite diversification. Results Most feather mite species (84%) inhabit one to three very closely related host species. Assemblages of feather mites on birds do not show a geographical signature, but rather show strong host‐driven structuring. The probability that a mite species occurs on two host species decays sharply with host phylogenetic distance, with only one instance of a feather mite species occupying distantly related hosts from different orders. However, results suggest that despite the strong host specificity, a few major host switches triggered the origin of 21% of the species and 38% of the genera of the mite families studied. Main conclusions We show that feather mites are highly host‐specific symbionts, whose assemblages do not show geographical structure, even at a continental scale. We conclude that major host switches are very rare events with strong macroevolutionary consequences for feather mite diversity.

Geographic distribution of data on bird-feather mite associations. Countries are coloured according to the number of records in a log-scale. Modified from Doña et al. (2016).

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Number of feather mite species per bird taxon. Values on the y-axis represent the number of mite species, and values on the x-axis represent the number of bird taxa. The panels, from left to right, depict bird species, genera, families and orders.

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Dendrogram representing feather mite community similarity (Jaccard distances) for populations of the same bird species in different supercontinents. All bird species with at least two supercontinents and with records of at least two feather mite species in each supercontinent are displayed. Each text color represents a different bird species. Each circle color represents a different supercontinent: America (orange), AsiaOce (blue), EurAfrica (green).

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Probability of that a bird pair with a mite in common have a particular phylogenetic distance. Close congeners have low distances, and species from different orders have the highest distance. As an example, dashed lines at the x-axis mark the phylogenetic distances between primary (Tree pipit Anthus trivialis) and secondary hosts inhabited by the mite Proctophyllodes anthi (see text for discussion). Secondary hosts, from left to the right: olive-backed pipit Anthus hodgsoni Richmond, western yellow wagtail Motacilla flava, woodlark Lullula arborea, Eurasian wryneck Jynx torquilla. Error bars represent confidence intervals (α = 0.05).

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Bird phylogenetic tree depicting the associations of mite genera of (a) Proctophyllodidae, (b) Trouessartiidae and (c) Pteronyssidae. Non-passerine hosts are those placed below the most external black semi-ring, and passerine hosts are those placed below the gray semi-ring. Blue: feather mite genera inhabiting only passerine hosts. Orange: mite genera inhabiting both passerine and non-passerine hosts. Green: mite genera inhabiting only non-passerine hosts. Numbers above the trees depict the total number of species and genera on passerine (values to the right) and non-passerine (values to the left) hosts for each mite family. Dotted arrows indicate direction of major host-switches, which for Proctophyllodidae and Trouessartiidae is from passerine to non-passerine hosts. Direction of switch for Pteronyssidae is uncertain (see text for details).

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Figures - uploaded by Jorge Doña

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Idiosyncrasy of feather mite intensity and prevalence across passerine bird species: a comparative study

Article

Full-text available

Feb 2025
OIKOS

Symbionts are key elements of ecosystems, by playing important roles in shaping the biology and ecology of their hosts. However, the factors determining symbiont loads across host species are still unclear. Nowadays, we know that the intensity and prevalence of feather mites, the most diverse group of avian ectosymbionts, differ strongly between species. To understand those differences, we studied 17 bird species traits and two feather mite community features (species richness and composition in bird species) potentially related to interspecific differences in feather mite intensity and prevalence across bird species. We analyzed a large dataset of feather mite occurrence across European passerines: for feather mite intensity a sample of 27 424 birds from 119 bird species, and 1 805 566 feather mites counted, and for prevalence a sample of 76 126 birds from 122 bird species. Feather mite intensity and prevalence covaried positively across bird species, reinforcing the previous observation that species differ in feather mite load. Comparative analyses of the association of bird traits and feather mite richness with feather mite intensity or prevalence showed a moderate explanatory power, high model selection uncertainty, inconsistent results for both prevalence and intensity data, and contrasting results with previous comparative studies on feather mite occurrence. Furthermore, even though closely related bird species had similar feather mite communities, there was a low evolutionary conservatism of both the prevalence and intensity of feather mites across bird species (i.e. low phylogenetic signal). Finally, feather mite community composition did not explain feather mite intensity or prevalence across bird species. Overall, our large number of host and mite traits failed to satisfactorily explain the high variability in feather mite occurrence across bird species. We discuss that this difficult‐to‐understand apparent idiosyncrasy of bird species in their feather mite intensity and prevalence may be the outcome of the interaction between host and symbiont traits.

Horizontal transmission maintains host specificity and codiversification of symbionts in a brood parasitic host

Article

Full-text available

Nov 2023

In host-symbiont systems, interspecific transmissions create opportunities for host switches, potentially leading to cophylogenetic incongruence. In contrast, conspecific transmissions often result in high host specificity and congruent cophylogenies. In most bird-feather mite systems, conspecific transmission is considered dominant, while interspecific transmission is supposedly rare. However, while mites typically maintain high host specificity, incongruent cophylogenies are common. To explain this conundrum, we quantify the magnitude of conspecific vs. interspecific transmission in the brood parasitic shiny cowbird (Molothrus bonariensis). M. bonariensis lacks parental care, allowing the assessment of the role of horizontal transmission alone in maintaining host specificity. We found that despite frequent interspecific interactions via foster parental care, mite species dispersing via conspecific horizontal contacts are three times more likely to colonize M. bonariensis than mites transmitted vertically via foster parents. The results highlight the previously underappreciated rate of transmission via horizontal contacts in maintaining host specificity on a microevolutionary scale. On a macroevolutionary scale, however, host switches were estimated to have occurred as frequently as codivergences. This suggests that macroevolutionary patterns resulting from rare events cannot be easily generalized from short-term evolutionary trends.

Diversity and structure of feather mite communities on seabirds from the north–east Atlantic and Mediterranean Sea

Article

Full-text available

Mar 2023

The richness and structure of symbiont assemblages are shaped by many factors acting at different spatial and temporal scales. Among them, host phylogeny and geographic distance play essential roles. To explore drivers of richness and structure of symbiont assemblages, feather mites and seabirds are an attractive model due to their peculiar traits. Feather mites are permanent ectosymbionts and considered highly host-specific with limited dispersal abilities. Seabirds harbour species-rich feather mite communities and their colonial breeding provides opportunities for symbionts to exploit several host species. To unravel the richness and test the influence of host phylogeny and geographic distance on mite communities, we collected feather mites from 11 seabird species breeding across the Atlantic Ocean and Mediterranean Sea. Using morphological criteria, we identified 33 mite species, of which 17 were new or recently described species. Based on community similarity analyses, mite communities were clearly structured by host genera, while the effect of geography within host genera or species was weak and sometimes negligible. We found a weak but significant effect of geographic distance on similarity patterns in mite communities for Cory’s shearwaters Calonectris borealis. Feather mite specificity mainly occurred at the host-genus rather than at host-species level, suggesting that previously inferred host species-specificity may have resulted from poorly sampling closely related host species. Overall, our results show that host phylogeny plays a greater role than geography in determining the composition and structure of mite assemblages and pinpoints the importance of sampling mites from closely-related host species before describing mite specificity patterns.

Extensive host-switching of avian feather lice following the Cretaceous-Paleogene mass extinction event

Article

Full-text available

Nov 2019

Nearly all lineages of birds host parasitic feather lice. Based on recent phylogenomic studies, the three major lineages of modern birds diverged from each other before the Cretaceous-Paleogene (K-Pg) mass extinction event. In contrast, studies of the phylogeny of feather lice on birds, indicate that these parasites diversified largely after this event. However, these studies were unable to reconstruct the ancestral avian host lineage for feather lice. Here we use genome sequences of a broad diversity of lice to reconstruct a phylogeny based on 1,075 genes. By comparing this louse evolutionary tree to the avian host tree, we show that feather lice began diversifying on the common ancestor of waterfowl and landfowl, then radiated onto other avian lineages by extensive host-switching. Dating analyses and cophylogenetic comparisons revealed that two of three lineages of birds that diverged before the K-Pg boundary acquired their feather lice after this event via host-switching. Robert de Moya et al. use comparative genomics of avian lice to reconstruct the phylogeny of these parasites. They show that feather lice diversified on the common ancestor of waterfowl and landfowl, and then radiated onto other avian lineages through host-switching.

Unexpected bird‐feather mite associations revealed by DNA metabarcoding uncovers a dynamic ecoevolutionary scenario

Article

Full-text available

Dec 2018

The high relevance of host‐switching for the diversification of highly host‐specific symbionts (i.e., those commonly inhabiting a single host species) demands a better understanding of host‐switching dynamics at an ecological scale. Here we used DNA metabarcoding to study feather mites on passerine birds in Spain, sequencing mtDNA (COI) for 25,540 individual mites (representing 64 species) from 1,130 birds (representing 71 species). Surprisingly, 1,228 (4.8%) mites from 84 (7.4%) birds were found on host species that were not the expected to be a host according to a recent bird‐feather mite associations catalog. Unexpected associations were widespread across studied mite (40.6%) and bird (43.7%) species and showed smaller average infrapopulation sizes than typical associations. Unexpected mite species colonized hosts being distantly related to the set of their usual hosts, but with similar body size. The network of bird‐mite associations was modular (i.e., some groups of bird and mite species tended to be more associated with each other than with the others), with 75.9% of the unexpected associations appearing within the module of the typical hosts of the mite species. Lastly, 68.4% of mite species found on unexpected hosts showed signatures of genetic differentiation, and we found evidence for reproduction or the potential for it in many of the unexpected associations. Results show host colonization as a common phenomenon even for these putatively highly host‐specific symbionts. Thus, host‐switching by feather mites, rather than a rare phenomenon, appears as a relatively frequent phenomenon shaped by ecological filters such as host morphology and is revealed as a fundamental component for a dynamic coevolutionary and codiversification scenario This article is protected by copyright. All rights reserved.

Feather mites play a role in cleaning host feathers: New insights from DNA metabarcoding and microscopy

Article

Full-text available

May 2018

Parasites and other symbionts are crucial components of ecosystems, regulating host populations and supporting food webs. However, most symbiont systems, especially those involving commensals and mutualists, are relatively poorly understood. In this study, we have investigated the nature of the symbiotic relationship between birds and their most abundant and diverse ectosymbionts: the vane‐dwelling feather mites. For this purpose, we studied the diet of feather mites using two complementary methods. First, we used light microscopy to examine the gut contents of 1,300 individual feather mites representing 100 mite genera (18 families) from 190 bird species belonging to 72 families and 19 orders. Second, we used high‐throughput sequencing (HTS) and DNA metabarcoding to determine gut contents from 1,833 individual mites of 18 species inhabiting 18 bird species. Results showed fungi and potentially bacteria as the main food resources for feather mites (apart from potential bird uropygial gland oil). Diatoms and plant matter appeared as rare food resources for feather mites. Importantly, we did not find any evidence of feather mites feeding upon bird resources (e.g., blood, skin) other than potentially uropygial gland oil. In addition, we found a high prevalence of both keratinophilic and pathogenic fungal taxa in the feather mite species examined. Altogether, our results shed light on the long‐standing question of the nature of the relationship between birds and their vane‐dwelling feather mites, supporting previous evidence for a commensalistic–mutualistic role of feather mites, which are revealed as likely fungivore–microbivore–detritivore symbionts of bird feathers.

Phylogenetic structure of specialization: A new approach that integrates partner availability and phylogenetic diversity to quantify biotic specialization in ecological networks

Article

Full-text available

Mar 2022

Biotic specialization holds information about the assembly, evolution, and stability of biological communities. Partner availabilities can play an important role in enabling species interactions, where uneven partner availabilities can bias estimates of biotic specialization when using phylogenetic diversity indices. It is therefore important to account for partner availability when characterizing biotic specialization using phylogenies. We developed an index, phylogenetic structure of specialization (PSS), that avoids bias from uneven partner availabilities by uncoupling the null models for interaction frequency and phylogenetic distance. We incorporate the deviation between observed and random interaction frequencies as weights into the calculation of partner phylogenetic α‐diversity. To calculate the PSS index, we then compare observed partner phylogenetic α‐diversity to a null distribution generated by randomizing phylogenetic distances among the same number of partners. PSS quantifies the phylogenetic structure (i.e., clustered, overdispersed, or random) of the partners of a focal species. We show with simulations that the PSS index is not correlated with network properties, which allows comparisons across multiple systems. We also implemented PSS on empirical networks of host–parasite, avian seed‐dispersal, lichenized fungi–cyanobacteria, and hummingbird pollination interactions. Across these systems, a large proportion of taxa interact with phylogenetically random partners according to PSS, sometimes to a larger extent than detected with an existing method that does not account for partner availability. We also found that many taxa interact with phylogenetically clustered partners, while taxa with overdispersed partners were rare. We argue that species with phylogenetically overdispersed partners have often been misinterpreted as generalists when they should be considered specialists. Our results highlight the important role of randomness in shaping interaction networks, even in highly intimate symbioses, and provide a much‐needed quantitative framework to assess the role that evolutionary history and symbiotic specialization play in shaping patterns of biodiversity. PSS is available as an R package at https://github.com/cjpardodelahoz/pss. We developed an approach to determine the phylogenetic structure of the partners that interact with a focal species while accounting for their availability. When applied in four empirical network datasets, we found that a large proportion of species interact with phylogenetically random partners.

Assessing symbiont extinction risk using cophylogenetic data

Article

Aug 2020
BIOL CONSERV

Symbionts have a unique mode of life that has attracted the attention of ecologists and evolutionary biologists for centuries. As a result of this attention, these disciplines have produced a mature body of literature on host-symbiont interactions. In contrast, the discipline of symbiont conservation is still in a foundational stage. Here, we aim to integrate methodologies for symbiont coevolutionary biology with symbiont conservation. We focus on host-symbiont cophylogenies, because they have been widely used to study symbiont diversification history and contain information on symbiont extinction. However, cophylogenetic information has never been used nor adapted to the perspective of conservation. Here, we propose a new statistic, “cophylogenetic extinction rate” (Ec), which is based on coevolutionary knowledge from event-based cophylogenetic analyses and could be informative to assess relative symbiont extinction risks. Finally, we propose potential future research to further develop methods to estimate symbiont extinction risk from cophylogenetic analyses, and to continue the integration of this existing knowledge of coevolutionary biology and cophylogenetics into future symbiont conservation studies and practices.

Persistence of single species of symbionts across multiple closely-related host species

Article

Full-text available

Nov 2019

Some symbiont species are highly host-specific, inhabiting only one or a very few host species, and typically have limited dispersal abilities. When they do occur on multiple host species, populations of such symbionts are expected to become genetically structured across these different host species, and this may eventually lead to new symbiont species over evolutionary timescales. However, a low number of dispersal events of symbionts between host species across time might be enough to prevent population structure and species divergence. Overall, processes of evolutionary divergence and the species status of most putative multi-host symbiont systems are yet to be investigated. Here, we used DNA metabarcoding data of 6,023 feather mites (a total of 2,225 OTU representative sequences) from 147 infracommunities (i.e., the assemblage consisting of all mites of different species collected from the same bird host individual) to investigate patterns of population genetic structure and species status of three different putative multi-host feather mite species Proctophyllodes macedo Vitzthum, 1922, Proctophyllodes motacillae Gaud, 1953, and Trouessartia jedliczkai (Zimmerman, 1894), each of which inhabits a variable number of different closely related wagtail host species (genus Motacilla). We show that mite populations from different host species represent a single species. This pattern was found in all the mite species, suggesting that each of these species is a multi-host species in which dispersal of mites among host species prevents species divergence. Also, we found evidence of limited evolutionary divergence manifested by a low but significant level of population genetic structure among symbiont populations inhabiting different host species. Our study agrees with previous studies showing a higher than expected colonization opportunities in host-specific symbionts. Indeed, our results support that these dispersal events would allow the persistence of multi-host species even in symbionts with limited dispersal capabilities, though additional factors such as the geographical structure of some bird populations may also play a role.

A newly discovered radiation of endoparasitic gastropods and their coevolution with asteroid hosts in Antarctica

Article

Full-text available

Dec 2019
BMC EVOL BIOL

Background: Marine invertebrates are abundant and diverse on the continental shelf in Antarctica, but little is known about their parasitic counterparts. Endoparasites are especially understudied because they often possess highly modified body plans that pose problems for their identification. Asterophila, a genus of endoparasitic gastropod in the family Eulimidae, forms cysts in the arms and central discs of asteroid sea stars. There are currently four known species in this genus, one of which has been described from the Antarctic Peninsula (A. perknasteri). This study employs molecular and morphological data to investigate the diversity of Asterophila in Antarctica and explore cophylogenetic patterns between host and parasite. Results: A maximum-likelihood phylogeny of Asterophila and subsequent species-delimitation analysis uncovered nine well-supported putative species, eight of which are new to science. Most Asterophila species were found on a single host species, but four species were found on multiple hosts from one or two closely related genera, showing phylogenetic conservatism of host use. Both distance-based and event-based cophylogenetic analyses uncovered a strong signal of coevolution in this system, but most associations were explained by non-cospeciation events. Discussion: The prevalence of duplication and host-switching events in Asterophila and its asteroid hosts suggests that synchronous evolution may be rare even in obligate endoparasitic systems. The apparent restricted distribution of Asterophila from around the Scotia Arc may be an artefact of concentrated sampling in the area and a low obvious prevalence of infection. Given the richness of parasites on a global scale, their role in promoting host diversification, and the threat of their loss through coextinction, future work should continue to investigate parasite diversity and coevolution in vulnerable ecosystems.

Host Specificity in Variable Environments

Article

Apr 2019
Trends Parasitol

Host specificity encompasses the range and diversity of host species that a parasite is capable of infecting and is considered a crucial measure of a parasite’s potential to shift hosts and trigger disease emergence. Yet empirical studies rarely consider that regional observations only reflect a parasite’s ‘realized’ host range under particular conditions: the true ‘fundamental’ range of host specificity is typically not approached. We provide an overview of challenges and directions in modelling host specificity under variable environmental conditions. Combining tractable modelling frameworks with multiple data sources that account for the strong interplay between a parasite's evolutionary history, transmission mode, and environmental filters that shape host–parasite interactions will improve efforts to quantify emerging disease risk in times of global change.

“More Than Meets the Eye”: Cryptic Diversity and Contrasting Patterns of Host-Specificity in Feather Mites Inhabiting Seabirds

Article

Full-text available

Jul 2018

Feather mites are useful models for studying speciation due to their high diversity and strong degree of host specialization. However, studies to date have focused on the evolution of higher-level mite taxa while much hidden diversity likely occurs at the level of host genera and species. In this study, we examined the diversity and evolution of feather mites infesting six sympatric seabird species from six genera, breeding in the Cape Verde archipelago. We report 32 feather mite morphospecies categorized into 10 genera and three families, of which nine correspond to new, undescribed species. Molecular data corroborated morphological species descriptions, except for two morphologically-cryptic, but genetically distinct mite lineages related to Zachvatkinia oceanodromae and Laminalloptes simplex. Using these communities, we then applied a co-structure approach to test the contribution of ectosymbiont and host factors in driving feather mite evolution. Most seabird species hosted specific and unique feather mite species, even under sympatric conditions, and in general, feather mite species exhibited strong host-driven genetic structure. However, patterns of genetic differentiation were variable. That is, some mite species are more generalist than others and mite lineages/haplotypes can be shared by related seabird species. Interestingly, host-specific mites (e.g., Zachvatkinia spp.) tend to display much higher intra-specific diversity compared to more generalist mites (e.g., Microspalax and Plicatalloptes spp.). We discuss ectosymbiont and host life-history traits that might generate these patterns, such as host dispersal and breeding behavior and/or mite spatial and trophic specialization. Our findings highlight both the vast and largely unrecognized diversity of avian feather mites on seabirds, and the intrinsic complexity of the ecological processes underlying the evolution of these ectosymbionts.

Phylogenetic uniqueness, not latitude, explains the diversity of avian blood parasite communities worldwide

Article

Full-text available

Nov 2017

Nicholas Clark

Aim Characterizing macroecological patterns in biodiversity is key to improve our understanding of community assembly. Global biodiversity for many taxa follows a latitudinal gradient, with increased diversity in tropical latitudes. Less is known about global parasite biodiversity, inhibiting our ability to predict how global change will impact parasitic disease emergence. Using distribution and phylogenetic data for 2,386 avian haemosporidian blood parasites (genera Plasmodium, Haemoproteus and Leucocytozoon), I assessed how contemporary and historical drivers influence the composition of parasite communities worldwide. Location Global. Time period Current. Major taxa studied Haemosporidian blood parasites. Methods Parasite distribution and cytochrome b sequence data were accessed from an open‐source database. Bayesian phylogenetic tree distributions were constructed for each parasite genus using two substitution models to capture uncertainty. Hierarchical regressions assessed effects of environmental variation, latitude and phylogenetic β‐diversity (βdiv; a proxy for phylogenetic uniqueness) on the diversity and asymmetry of parasite communities around the globe. Results I uncovered biodiversity hotspots and identified broad variation in global diversity patterns among parasite genera. Community diversity increased with increasing phylogenetic uniqueness for all three parasite genera; however, these diverse and unique regions did not consistently occur in the tropics. I found no evidence of a latitudinal diversity gradient, and support for a latitudinal gradient in community phylogenetic asymmetry was weak. Main conclusions Global variation in avian haemosporidian phylogenetic diversity does not reflect a latitudinal gradient. Instead, parasite biogeography may reflect fundamental differences in host‐switching tendencies or the timing of avian evolutionary radiations. Examining the interplay between shared evolutionary history and phylogenetic diversity can provide important insights into the drivers of parasite biodiversity at global scales.

Cophylogenetic assessment of New World warblers (Parulidae) and their symbiotic feather mites (Proctophyllodidae)

Article

Full-text available

Mar 2018

Host-symbiont relationships are ubiquitous in nature, yet evolutionary and ecological processes that shape these intricate associations are often poorly understood. All orders of birds engage in symbioses with feather mites, which are ectosymbiotic arthropods that spend their entire life on hosts. Due to their permanent obligatory association with hosts, limited dispersal, and primarily vertical transmission, we hypothesized that the cospeciation between feather mites and hosts within one avian family (Parulidae) would be perfect (strict cospeciation). We assessed cophylogenetic patterns and tested for congruence between species in two confamiliar feather mite genera (Proctophyllodidae: Proctophyllodes, Amerodectes) found on 13 species of migratory warblers (and one other closely related migratory species) in the eastern United States. Based on COI sequence data, we found three Proctophyllodes lineages and six Amerodectes lineages. Distance- and event-based cophylogenetic analyses suggested different cophylogenetic trajectories of the two mite genera, and although some associations were significant, there was little overall evidence supporting strict cospeciation. Host switching is likely responsible for incongruent phylogenies. In one case, we documented Prairie Warblers (Setophaga discolor) harboring two mite species of the same genus. Most interestingly, we found strong evidence that host ecology may influence the likelihood of host switching occurring. For example, we documented relatively distantly related ground-nesting hosts (Ovenbird, Seiurus aurocapilla, and Kentucky Warbler, Geothlypis formosa) sharing a single mite species, while other birds are shrub/canopy or cavity nesters. Overall, our results suggest that cospeciation is not the case for feather mites and parulid hosts at this fine phylogenetic scale, and raise the question if cospeciation applies for other symbiotic systems involving hosts that have complex life histories. We also provide preliminary evidence that incorporating host ecological traits into cophylogenetic analyses may be useful for understanding how symbiotic systems have evolved.

Occurrence of Echinococcus felidis in Apex Predators and Warthogs in Tanzania: First Molecular Evidence of Leopards as a New, Definitive Host and Implications for Ecosystem Health

Article

Full-text available

Apr 2025

(1) Background: Limited information on Echinococcus species among the wildlife in Tanzania has created a significant knowledge gap regarding their distribution, host range, and zoonotic potential. This study aimed to enhance the understanding of Echinococcus felidis transmission dynamics within the great Serengeti ecosystem. (2) Methods: A total of 37 adult Echinococcus specimens were collected from a leopard (Panthera pardus) (n = 1) in Maswa Game Reserve and 7 from a lion (Panthera leo) (n = 1) in Loliondo. Two hydatid cysts were also obtained from warthogs (n = 2) in the Serengeti National Park. (3) Results: Morphological examination revealed infertile cysts in warthogs that were molecularly identified as E. felidis. This marks the first molecular evidence of E. felidis in leopards and warthogs in Tanzania. Pairwise similarity analysis showed 98.7%–99.5% identity between Tanzanian, Ugandan, and South African isolates. Thirteen unique haplotypes were identified, with a haplotype diversity of (Hd = 0.9485) indicating genetic variability. Phylogenetic analysis grouped E. felidis into a single lineage, with the leopard isolate forming a distinct haplotype, suggesting leopards as an emerging host. Lion and warthog isolates shared multiple mutational steps, suggesting possible genetic divergence. (4) Conclusions: This study confirms African lions and leopards as definitive hosts and warthogs as potential intermediate hosts of E. felidis in the Serengeti ecosystem. Our findings highlight disease spillover risks and stress the importance of ecosystem-based conservation in wildlife–livestock overlap areas. Although E. felidis is believed to be confined to wildlife, the proximity of infected animals to pastoralist communities raises concerns for spillover. These findings highlight the importance of ecosystem-based surveillance, especially in wildlife–livestock–human interface areas.

Geography is a stronger predictor of diversification of monogenean parasites (Platyhelminthes) than host relatedness in characin fishes of Middle America

Article

Full-text available

Apr 2025
PLOS ONE

Host-parasite associations have historically been considered compelling examples of coevolution and useful in examining cospeciation. However, modern molecular methods have revealed more complex dynamics than previously assumed, with host-switching events appearing commonly across taxa and challenging traditional views of strict coevolution in host-parasite relationships. Monogenean parasites are considered highly host-specific and have long served as models for probing evolution of host-parasite associations, particularly in differentiating geographic and phylogenetic patterns of parasite diversification. We investigated the phylogeographic patterns of monogenean ectoparasites associated with four species of characin fishes across Panama, Nicaragua, and Mexico. We hypothesize that parasite diversity and community structure are more strongly correlated with host species (suggesting cospeciation) than with geographic location (indicative of allopatric speciation). We found high genetic differentiation among parasites and their hosts across different locations. However, while geography explained the genetic structure of both host fishes and parasites, the observed patterns were neither congruent nor parallel. Parasite community structure and genetic similarity were consistently better explained by geographic location than by host species identity, although both factors played a significant role. Contrary to our predictions, we found no evidence of cospeciation. Instead, the diversification of these monogenean parasites appears to be primarily driven by their ability to switch hosts. At this taxonomical scale, host-switching is mediated by the geographical proximity of potential hosts, underscoring the importance of spatial factors in parasite evolution.

Prevalence and size variation of feather mite, Analges slovakiensis Dabert, Mironov & Janiga, 2018, on the host Alpine accentor, Prunella collaris (Scopoli, 1769)

Article

Full-text available

Jan 2025

Analges slovakiensis Dabert, Mironov and Janiga, 2018 is a mite species that has co-evolved with the Alpine accentor Prunella collaris(Scopoli, 1786), an alpine songbird. We captured 150 Alpine accentors in the Western Carpathians in Slovakia to study the ecology and morphology of Analges slovakiensis. Seasonal variations in size were found only in females. In spring, female mites were larger with a higher intensity of infestation, however with the lowest prevalence. In contrast, autumn generations of female mites were smaller and the intensity of infestation by mites was lower due to a large dispersal to host birds. The prevalence of mites was high in autumn and in summer. Males of A. slovakiensis did not differ in size or shape among seasons. Morpho-physiological plasticity combined with population dynamics allows the mites to survive effectively on hosts living at high altitudes in the mountains. The results also suggest that A. slovakiensis spreads through vertical transmission, as it radiates and increases in size during breeding season.

A New Feather Mite Species of the Genus Metanalges (Acariformes: Analgidae) from the Okinawa Rail, Hypotaenidia okinawae (Gruiformes: Rallidae), in Okinawa Island, Japan

Article

Full-text available

Apr 2024

The Okinawa Rail, Hypotaenidia okinawae (Yamashina and Mano, 1981), is a flightless bird restricted to the northern part of Okinawa Island, Ryukyu Islands, Japan. A new feather mite species, Metanalges (M.) agachi sp. n. (Analgidae: Megniniinae), is described from the Okinawa Rail. The new species is distinguished from the closest species, M. (M.) curtus Gaud and Mouchet, 1959, in having, in males, legs III extending slightly beyond the bases of setae h2, and setae ps1 approximately equidistant from setae h2 and h3, and in females, ventral setae 4a almost extending to the posterior margin of opisthosoma. This is the first report of feather mites associated with this avian host and the first record of the genus Metanalges Trouessart, 1919 in Japan. As the Okinawa Rail is considered to be at high risk of population decline, the new feather mite is thought to be under the risk of extinction.

Novel insights into symbiont population structure: Globe-trotting avian feather mites contradict the specialist-generalist variation hypothesis

Article

Full-text available

Aug 2023
MOL ECOL

Researchers often examine symbiont host specificity as a species-level pattern, but it can also be key to understanding processes occurring at the population level, which are not as well understood. The specialist-generalist variation hypothesis (SGVH) attempts to explain how host specificity influences population-level processes, stating that single-host symbionts (specialists) exhibit stronger population genetic structure than multi-host symbionts (generalists) because of fewer opportunities for dispersal and more restricted gene flow between populations. However, this hypothesis has not been tested in systems with highly mobile hosts, in which population connectivity may vary temporally and spatially. To address this gap, we tested the SGVH on proctophyllodid feather mites found on migratory warblers (family Parulidae) with contrasting host specificities, Amerodectes protonotaria (a host specialist of Protonotaria citrea) and A. ischyros (a host generalist of 17 parulid species). We used a pooled-sequencing approach and a novel workflow to analyse genetic variants obtained from whole genome data. Both mite species exhibited fairly weak population structure overall, and contrary to predictions of the SGVH, the generalist was more strongly structured than the specialist. These results may suggest that specialists disperse more freely among conspecifics, whereas generalists sort according to geography. Furthermore, our results may reflect an unexpected period for mite transmission - during the nonbreeding season of migratory hosts - as mite population structure more closely reflects the distributions of hosts during the nonbreeding season. Our findings alter our current understanding of feather mite biology and highlight the potential for studies to explore factors driving symbiont diversification at multiple evolutionary scales.

A Review of the Feather Mite Genus Lopharalichus Gaud & Atyeo, 1996 (Acariformes: Pterolichidae), with Descriptions of Three New Species from Brazilian Parrots (Psittaciformes: Psittacidae)

Article

Full-text available

Jul 2023

Fabio Akashi Hernandes

Simple Summary Understanding the current biodiversity of our planet is an ongoing challenge, as natural habitats are being destroyed at a faster rate than species are described. This is especially true for South America, which harbors over one-third of the parrot species in the world. A diverse yet poorly studied group of mites associated with birds are feather mites, which currently include about 2500 known species, and estimates range from 10,000 to 20,000 species. Herein, three new species of feather mites of the genus Lopharalichus are described from parrots in Brazil. Abstract Feather mites of the genus Lopharalichus Gaud & Atyeo, 1996 (Pterolichidae: Pterolichinae), formerly containing three described species, are associated with New World parrots (Psittaciformes: Psittacidae) of the subfamily Arinae. Three new species of this genus are described: Lopharalichus tuim sp. nov. from Forpus xanthopterygius (Spix, 1824), L. spinosus sp. nov. from Ara ararauna (Linnaeus, 1758), and L. chiriri sp. nov. from Brotogeris chiriri (Vieillot, 1818). Type specimens of the previously described Lopharalichus species were examined, and a key to the known species is provided.

Ácaros plumícolas (Acariformes: Pterolichoidea y Analgoidea) de México: relaciones huésped- ectosimbionte bajo un enfoque de análisis de redes

Article

Jul 2023

Los ácaros plumícolas son ectosimbiontes de aves con alta especificidad debido a su ciclo de vida permanente, distribuirse en micrositios particulares de las plumas y por su transmisión vertical. El objetivo de este trabajo fue recopilar la información disponible del grupo en México y analizar los patrones de distribución en sus huéspedes bajo un enfoque de análisis de redes. Para ello, se recuperaron los registros del grupo a través de búsquedas bibliográficas especializadas excluyendo la literatura gris. Los datos se organizaron en unamatriz de presencia y ausencia para construir una red bipartita dirigida. En este análisis se calcularon índices a nivel de red (conectancia, asimetría de la red, enlace por taxón y número de compartimientos) y de nodo (grado e intermediación) para tres niveles: orden, familia y género de huéspedes. Debido a que varios taxones de ácaros plumícolas reportados en el país no han sido identificados hasta el nivel deespecie los análisis se realizaron a nivel genérico. De acuerdo con los datos obtenidos, en el país se han registrado 50 géneros de ácaros plumícolas distribuidos en 17 familias. De este total, se han reportado 95 especies nominales. Los 50 géneros han sido encontrados en asociación con 128 especies de aves, distribuidas en 93 géneros, 30 familias y 13 órdenes. Los órdenes de huéspedes que representan mayor número de interacciones son Passeriformes, Psittaciformes, Pelecaniformes y Apodiformes. Los índices a nivel de red muestran que la especificidad de los ácaros plumícolas es alta. Por otro lado, a nivel de nodo los géneros Proctophyllodes y Nycteridocaulus sonlos que poseen un mayor valor de grado e intermediación. Se discute la asimetría geográfica de su estudio en el país encontrando que muchos de los estudios se han concentrado en la vertiente del Golfo de México y en grupos de huéspedes particulares.

Explosive networking: The role of adaptive host radiations and ecological opportunity in a species‐rich host–parasite assembly

Article

Full-text available

Jun 2022
ECOL LETT

Many species‐rich ecological communities emerge from adaptive radiation events. Yet the effects of adaptive radiation on community assembly remain poorly understood. Here, we explore the well‐documented radiations of African cichlid fishes and their interactions with the flatworm gill parasites Cichlidogyrus spp., including 10,529 reported infections and 477 different host–parasite combinations collected through a survey of peer‐reviewed literature. We assess how evolutionary, ecological, and morphological parameters determine host–parasite meta‐communities affected by adaptive radiation events through network metrics, host repertoire measures, and network link prediction. The hosts' evolutionary history mostly determined host repertoires of the parasites. Ecological and evolutionary parameters predicted host–parasite interactions. Generally, ecological opportunity and fitting have shaped cichlid‐Cichlidogyrus meta‐communities suggesting an invasive potential for hosts used in aquaculture. Meta‐communities affected by adaptive radiations are increasingly specialised with higher environmental stability. These trends should be verified across other systems to infer generalities in the evolution of species‐rich host–parasite networks. Many species‐rich ecological communities result from adaptive radiation events. We investigate interactions of African cichlids and their flatworm parasites belonging to Cichlidogyrus (a) through network analyses (b), host repertoire estimation, and network link prediction (heatmaps) (c). The hosts’ evolutionary history and environment determine observed host repertoires and network structure (b) but cichlid radiations in Eastern Africa have formed more specialised host‐parasite communities (c).

Differential survival and dispersal of avian feather mites with contrasting host specificities

Article

Full-text available

Jun 2022

Host specificity is a fundamental life history trait of symbionts and exists on a broad continuum from symbionts that are specific to one or a few hosts (host specialists), to those associated with multiple different host species (host generalists). However, the biological mechanisms underlying the complexity and wide variation in symbiont host specificity are poorly understood from both the symbiont and host perspectives across many symbiotic systems. Feather mites are common avian symbionts that vary in their host specificity from extreme host generalists to host specialists, even among species within the same genus. Here, we measured and compared survival probability and rate of dispersal to determine how these traits differ between two species of feather mites in the same genus: one host generalist associated with 17 host species ( Amerodectes ischyros ) and one host specialist with only one known host ( A. protonotaria ). We initially predicted that the host generalist would live longer and disperse more rapidly but discovered that while the host generalist mite survived longer, the host specialist mite dispersed more quickly. The differing environmental and ecological conditions in which the hosts of these mites are associated may explain the survival and dispersal patterns we uncovered, as differential microclimates may have led to different selective pressures on each species of mite. We also noted mite behavioural observations and suggest experiments to extend our understanding of feather mite ecology and evolution.

Ecological factors driving the feather mite associations in tropical avian hosts

Article

Full-text available

Apr 2022
J AVIAN BIOL

Birds host a diversity of ectosymbionts including feather‐dwelling arthropods such as feather mites and lice that they have co‐evolved and speciated with. Among these ectosymbionts, feather mites have evolved more mutualistic to commensal associations with birds than other groups. However, our understanding of the biological and ecological drivers that shape the associations between avian hosts and feather mites in tropical communities is poor. Thus, to help fill this knowledge gap we investigated the factors that govern feather mite abundances at host community, host species and individual levels in bird communities from different elevations on the tropical island of New Guinea. We examined the effects of abiotic factors, such as temperature and precipitation, the influence of host species, feeding guilds, bill morphology, body region, body conditions and infections with haemosporidian blood parasites on feather mite abundance. We found that feather mites were very prevalent among New Guinean birds and that mite abundance was not significantly different between elevations. Bird species with curved bills experienced significantly lower number of mites compared to species with straight bills. Feather mite abundance was significantly higher on flight feathers than on the rest of the body and mite abundance was not strongly associated with the body condition of individuals in most host species, except for a significant negative relationships in three species. Moreover, we did not find an association between feather mite abundance and blood parasite infections, potentially indicating a non‐synergistic association of these two symbionts. Overall, our study demonstrates that tropical avian‐feather mite associations are driven by different biotic and abiotic factors at host community, species and individual levels, highlighting the importance of examining these associations at both broad and fine scales to thoroughly understand the evolution of these symbioses.

Feather mites at night: an exploration of their feeding, reproduction, and spatial ecology

Article

Full-text available

Nov 2021
ECOLOGY

Birds host a vast diversity of feather symbionts of different kingdoms, including animals (e.g., lice, mites), fungi, and bacteria. Feather mites (Acariformes: Astigmata: Analgoidea and Pterolichoidea), the most abundant animal ectosymbionts of birds, are permanent inhabitants of the pterosphere (ptero feather in Greek; Labrador et al. 2020), and the ones studied here are easily spotted as small (ca. 0.5mm) dots on the surface of flight feathers. They are highly host specific symbionts (Doña et al. 2017), and they seem to be commensalistic or even mutualists of birds by taking detritus and microorganisms such as fungi and bacteria from feathers, some of which are keratinophilic and thus can damage the feathers (Blanco et al. 1997, Galván et al. 2012, Doña et al. 2018). However, many basic questions remain to be answered, such as the moments and the places where feather mites eat. Indeed, we wondered whether this might be partly because feather mites have been studied mainly during the day, when (most) birds fly, rather than during the night when mites seem to move more freely on the wings, according to two old anecdotal reports (Dubinin 1951, McClure 1989). To investigate the night ecology of feather mites, we initially spent a whole night observing them on two individual birds. At that point, we were unaware of how it would change our understanding of the pterosphere.

The ghost of hosts past: Impacts of host extinction on parasite specificity

Article

Full-text available

Sep 2021

A growing body of research is focused on the extinction of parasite species in response to host endangerment and declines. Beyond the loss of parasite species richness, host extinction can impact apparent parasite host specificity, as measured by host richness or the phylogenetic distances among hosts. Such impacts on the distribution of parasites across the host phylogeny can have knock-on effects that may reshape the adaptation of both hosts and parasites, ultimately shifting the evolutionary landscape underlying the potential for emergence and the evolution of virulence across hosts. Here, we examine how the reshaping of host phylogenies through extinction may impact the host specificity of parasites, and offer examples from historical extinctions, present-day endangerment, and future projections of biodiversity loss. We suggest that an improved understanding of the impact of host extinction on contemporary host–parasite interactions may shed light on core aspects of disease ecology, including comparative studies of host specificity, virulence evolution in multi-host parasite systems, and future trajectories for host and parasite biodiversity. This article is part of the theme issue ‘Infectious disease macroecology: parasite diversity and dynamics across the globe’.

The explosive radiation, intense host-shifts and long-term failure to speciate in the evolutionary history of the feather mite genus Analges (Acariformes: Analgidae) from European passerines

Article

Jan 2021

Mites of the genus Analges (Acariformes: Analgidae) inhabit the down feathers of passeriform birds. The evolutionary history of Analges and the co-phylogentic relationships between these mites and their hosts are unknown. Our phylogenetic analysis supported the monophyly of the genus, but it did not support previous taxonomic hypotheses subdividing the genus into the subgenera Analges and Analgopsis or arranging some species into the A. chelopus and A. passerinus species groups. Molecular data reveal seven new species inhabiting Eurasian passerines and support the existence of several multi-host species. According to molecular dating, the origin of the Analges (c. 41 Mya) coincided with the Eocene diversification of Passerida into Sylvioidea and Muscicapoidea–Passeroidea. The initial diversification of Analges took place on the Muscicapoidea clade, while remaining passerine superfamilies appear to have been colonized because of host-switching. Co-speciation appears to be relatively common among Analges species and their hosts, but the most striking pattern in the co-phylogenetic scenario involves numerous complete host-switches, spreads and several failures to speciate. The mechanism of long-term gene-flow among different populations of multi-host Analges species is enigmatic and difficult to resolve. Probably, in some cases mites could be transferred between birds via feathers used as nest material.

The explosive radiation, intense host-shifts and long-term failure to speciate in the evolutionary history of the feather mite genus Analges (Acariformes: Analgidae) from European passerines

Article

Aug 2021

Evolution of protective symbiosis in palaemonid shrimps (Decapoda: Caridea) with emphases on host spectrum and morphological adaptations

Article

May 2021
MOL PHYLOGENET EVOL

Palaemonidae is the most speciose caridean shrimp family, with its huge biodiversity partially generated via symbiosis with various marine invertebrates. Previous studies have provided insights into the evolution of protective symbiosis in this family with evidence for frequent inter-phyla host switches, but the comprehensiveness of evolutionary pathways is hampered by the resolution of the previous phylogenetic trees as well as the taxon coverage. Furthermore, several critical issues related to the evolution of a symbiotic lifestyle, including the change in host spectrum and corresponding morphological adaptations, remain largely unresolved. We therefore performed a much extended phylogenetic comparative study on Palaemonidae, rooted in a comprehensive phylogeny reconstructed by a supermatrix-supertree approach based on a total of three mitochondrial and five nuclear markers. Ancestral state reconstruction of host associations revealed at least three independent evolutions into symbiosis, with potentially a drive to seek protection fuelling incipient symbiosis. Yet, most of the observed symbiotic species diversity was radiated from a single cnidarian associate. The evolution of mandibles and ambulatory dactyli suggests a general lack of correlation with host affiliation (except sponge endosymbionts), implying limited morphological adaptations following host switching, despite being putatively a major adaptive consequence of symbiosis. Our analyses of host spectrum, in terms of basic and taxonomic specificity, revealed no apparent phylogenetic signal but instead resolved a dynamic pattern attributable to frequent host switching. Uncoupling between host spectrum and the degree of morphological specialisation is the norm in palaemonids, suggesting that morphological characters are not fully in tune with host spectrum, in addition to host affiliation. This study demonstrates the complexity in the evolution of symbiosis, pointing to the presence of cryptic adaptations determining host spectrum and governing host switch diversification, and provides a clear direction for the evolutionary study of symbiosis in other marine symbiotic groups involving host switching.

Drivers of compositional turnover are related to species’ commonness in flea assemblages from four biogeographic realms: zeta diversity and Multi-Site Generalised Dissimilarity Modelling

Article

Mar 2020
Int J Parasitol

We investigated drivers of species turnover in fleas parasitic on small mammals in four biogeographic realms using novel methodology (zeta diversity, and Multi-Site Generalised Dissimilarity Modelling (MS-GDM)). We asked whether (i) flea turnover was better explained by host turnover or environmental variables; (ii) different factors drive the turnover of rare and widespread fleas; (iii) the factors affecting the turnover of rare or widespread fleas differ between realms; and (iv) environmental variables drive flea turnover directly or via their effects on hosts. Dissimilarity in host species composition was the most important factor affecting flea turnover in all realms. In the Afrotropics, the Nearctic, and the Neotropics, this was true mainly for rare species, whereas the zeta diversity of the Palearctic hosts exerted a strong effect on the turnover of both rare and widespread fleas. Dissimilarity in temperature contributed the most to the turnover of rare fleas in the Neotropics and the Palearctic, whereas the turnover of widespread species in these realms was strongly affected by dissimilarity in precipitation. In the Nearctic, dissimilarity in precipitation or temperature mostly affected the turnover of rare fleas or common species, respectively. In the Afrotropics, dissimilarity in the Normalized Difference Vegetation Index (NDVI) and temperature affected the turnover of all species, independently of their level of commonness, while dissimilarity in rainfall was important for the turnover of rare fleas. The responses of flea assemblages to environmental factors represented a combination of direct responses and responses mediated via effects on host turnover. We conclude that host turnover is a more important factor than environmental dissimilarity in its effect on flea species turnover. However, the relative effects of host composition and environment, as well as those of temperature, precipitation and the amount of vegetation, on flea turnover differ (i) between realms and (ii) between rare and common fleas.

Feather mites (Acari: Astigmata) of the Zoobotanical State Park in Teresina, Brazil

Article

Oct 2019

Feather mites are the most diverse avian ectoparasites. They mainly live on the plumage of birds, feeding on uropygial oil, and may occasionally cause skin irritation, especially on caged birds. Here we report the results of a survey of feather mites on wild birds of the Zoobotanical State Park of Teresina, Piauí, Brazil. The following mites were collected from seven bird specimens kept in the park from January to July 2017: Pandionacarus fuscus (Nitzsch, 1818) on the osprey (Pandion haliaetus); Freyana dendrocygni Dubinin, 1950 and Heterobrephosceles megathrix Peterson and Atyeo, 1977 on the white-faced whistling-duc (Dendrocygna viduata); Nyctibiolichus megamerus Atyeo, 1979 on the common potoo (Nyctibius griseus); Hieracolichus hirundo (Mégnin and Trouessart, 1884) on the harpy eagle (Harpia harpyja) and Hieracolichus sp. on the southern caracara (Caracara plancus). These findings increase the known ranges of the mite species, with four of them reported for the first time in Brazil.

Assessing symbiont extinction risk using cophylogenetic data

Preprint

Full-text available

Jan 2020

Symbionts have a unique mode of life that has attracted the attention of ecologists and evolutionary biologists for centuries. As a result of this attention, these disciplines have produced a mature body of literature on host-symbiont interactions. In contrast, the discipline of symbiont conservation is still in a foundational stage. Here, we aim to integrate methodologies on symbiont coevolutionary biology with the perspective of conservation. We focus on host-symbiont cophylogenies, because they have been widely used to study symbiont diversification history and contain information on symbiont extinction. However, cophylogenetic information has never been used nor adapted to the perspective of conservation. Here, we propose a new statistic, “cophylogenetic extinction rate” (Ec), based on coevolutionary knowledge, that uses data from event-based cophylogenetic analyses, and which could be informative to assess relative symbiont extinction risks. Finally, we propose potential future research to further develop estimation of symbiont extinction risk from cophylogenetic analyses and continue the integration of this existing knowledge of coevolutionary biology and cophylogenetics into future symbiont conservation studies and practices.

Deeply conserved susceptibility in a multi‐host, multi‐parasite system

Article

Full-text available

Mar 2019
ECOL LETT

Variation in susceptibility is ubiquitous in multi‐host, multi‐parasite assemblages, and can have profound implications for ecology and evolution in these systems. The extent to which susceptibility to parasites is phylogenetically conserved among hosts can be revealed by analysing diverse regional communities. We screened for haemosporidian parasites in 3983 birds representing 40 families and 523 species, spanning ~ 4500 m elevation in the tropical Andes. To quantify the influence of host phylogeny on infection status, we applied Bayesian phylogenetic multilevel models that included a suite of environmental, spatial, temporal, life history and ecological predictors. We found evidence of deeply conserved susceptibility across the avian tree; host phylogeny explained substantial variation in infection status, and results were robust to phylogenetic uncertainty. Our study suggests that susceptibility is governed, in part, by conserved, latent aspects of anti‐parasite defence. This demonstrates the importance of deep phylogeny for understanding present‐day ecological interactions.

Climate variation influences host specificity in avian malaria parasites

Article

Full-text available

Jan 2019
ECOL LETT

Parasites with low host specificity (e.g. infecting a large diversity of host species) are of special interest in disease ecology, as they are likely more capable of circumventing ecological or evolutionary barriers to infect new hosts than are specialist parasites. Yet for many parasites, host specificity is not fixed and can vary in response to environmental conditions. Using data on host associations for avian malaria parasites (Apicomplexa: Haemosporida), we develop a hierarchical model that quantifies this environmental dependency by partitioning host specificity variation into region‐ and parasite‐level effects. Parasites were generally phylogenetic host specialists, infecting phylogenetically clustered subsets of available avian hosts. However, the magnitude of this specialisation varied biogeographically, with parasites exhibiting higher host specificity in regions with more pronounced rainfall seasonality and wetter dry seasons. Recognising the environmental dependency of parasite specialisation can provide useful leverage for improving predictions of infection risk in response to global climate change.

Global patterns in helminth host specificity: phylogenetic and functional diversity of regional host species pools matter

Article

Full-text available

Oct 2018
ECOGRAPHY

Host specificity has a major influence on a parasite's ability to shift between human and animal host species. Yet there is a dearth of quantitative approaches to explore variation in host specificity across biogeographical scales, particularly in response to the varying community compositions of potential hosts. We built a global dataset of intermediate host associations for nine of the world's most widespread helminth parasites (all of which infect humans). Using hierarchical models, we asked if realised parasite host specificity varied in response to regional variation in the phylogenetic and functional diversities of potential host species. Parasites were recorded in 4–10 zoogeographical regions, with some showing considerable geographical variation in observed versus expected host specificity. Parasites generally exhibited the lowest phylogenetic host specificity in regions with the greatest variation in prospective host phylogenetic diversity, namely the Neotropical, Saharo‐Arabian and Australian regions. Globally, we uncovered notable variation in parasite host shifting potential. Observed host assemblages for Hydatigera taeniaeformis and Hymenolepis diminuta were less phylogenetically diverse than expected, suggesting limited potential to spillover into unrelated hosts. Host assemblages for Echinococcus granulosus, Mesocestoides lineatus and Trichinella spiralis were less functionally diverse than expected, suggesting limited potential to shift across host ecological niches. By contrast, Hyd. taeniaeformis infected a higher functional diversity of hosts than expected, indicating strong potential to shift across hosts with different ecological niches. We show that the realised phylogenetic and functional diversities of infected hosts are determined by biogeographical gradients in prospective host species pools. These findings emphasise the need to account for underlying species diversity when assessing parasite host specificity. Our framework to identify variation in realised host specificity is broadly applicable to other host–parasite systems and will provide key insights into parasite invasion potential at regional and global scales.

Four new feather mite species of the genus Amerodectes Valim & Hernandes (Acariformes: Proctophyllodidae) from New World warblers (Passeriformes: Parulidae) in the USA

Article

Full-text available

May 2018

Four new feather mite species of the genus Amerodectes Valim & Hernandes, 2010 (Proctophyllodidae: Pterodectinae) are described from New World warblers (Passeriformes: Parulidae) of USA: Amerodectes ischyros sp. nov. from Setophaga caerulescens (Gmelin, 1789), A. charitomenos sp. nov. from S. dominica (Linnaeus, 1766), A. protonotaria sp. nov. from Protonotaria citrea (Boddaert, 1783), and A. jonesborensis sp. nov. from Parkesia noveboracensis (Gmelin, 1789). Information on the DNA barcode sequence of these four species was also analyzed.

Different life strategies of closely related louse species in sympatry: specialist and „generalist“ lineages of Polyplax serrata

Article

Oct 2024
Int J Parasitol

Ecomorphological convergence in the walking leg dactyli of two clades of ascidian-and mollusc-associated shrimps (Decapoda: Caridea: Palaemonidae)

Article

Full-text available

Dec 2023

Symbiotic species, living within or on the surface of host organisms, may evolve a wide range of adaptations as a result of various selection pressures, host specificity of the symbiont and the nature of the symbiosis. In tropical marine coral reef ecosystems, palaemonid shrimps (Crustacea: Decapoda: Caridea) live in association with at least five different invertebrate phyla. Host switches between (distantly) related host groups, and the thereby associated selection pressures were found to play a major role in the diversification of these shrimp lineages, giving rise to various host-specific adaptations. Two lineages of palaemonid shrimp, which have switched from an ectosymbiotic association towards endosymbiosis, are studied for their morphological diversification and possible convergence. Special attention is given to the between-phyla host switches involving ascidian and bivalve hosts, which are characteristic for these lineages. Using landmark-based (phylo)morphospace analyses and Scanning Electron Microscopy, the walking leg dactylus shape and the microstructures on these dactyli are studied. No specific bivalve-or ascidian-associated morphotypes were found, but morphological convergence in dactylus morphology was found in various species within the two studied clades with similar host groups. In addition, multiple lineages of bivalve-associated species appear to be morphologically diverging more than their ascidian-associated relatives, with 'intermediate' morphotypes found near host-switching events.

Prelude to a study of the feather mites of Australia (Acariformes: Astigmata)

Article

May 2023

R.B. HALLIDAY

This paper reviews the state of knowledge of the feather mites of Australia (Arachnida: Acariformes: Astigmata). The known fauna includes 149 species arranged in 95 genera and 24 families, in the Superfamilies Analgoidea and Pterolichoidea. A checklist of the fauna is provided, including bibliographic details for every species and genus. The bird host and collecting localities are listed for every species, and taxonomic and nomenclatural problems are discussed where necessary. The total fauna may include as many as 800 undescribed species. The checklist is preceded by a brief review of some aspects of the biology of feather mites, which have not been studied in the context of the Australian fauna.The correct spelling for a family of respiratory tract parasites is confirmed as Kytoditidae. Dabertia indistincta (Dabert & Atyeo, 1993) comb. n. (Syringobiidae) and Hemialges australis (Trouessart, 1885) comb. n. (Analgidae) are new combinations proposed herein.

Dispersal-Limited Symbionts Exhibit Unexpectedly Wide Variation in Host Specificity

Article

Full-text available

Mar 2023
SYST BIOL

A fundamental aspect of symbiotic relationships is host specificity, ranging from extreme specialists associated with only a single host species to generalists associated with many different species. Although symbionts with limited dispersal capabilities are expected to be host specialists, some are able to associate with multiple hosts. Understanding the micro- and macroevolutionary causes of variations in host specificity is often hindered by sampling biases and the limited power of traditional evolutionary markers. Here, we studied feather mites to address the barriers associated with estimates of host specificity for dispersal-limited symbionts. We sampled feather mites (Proctophyllodidae) from a nearly comprehensive set of North American breeding warblers (Parulidae) to study mite phylogenetic relationships and host-symbiont codiversification. We used pooled-sequencing (Pool-Seq) and short-read Illumina technology to interpret results derived from a traditional barcoding gene (cytochrome c oxidase subunit 1) versus 11 protein-coding mitochondrial genes using concatenated and multispecies coalescent approaches. Despite the statistically significant congruence between mite and host phylogenies, mite-host specificity varies widely, and host switching is common regardless of the genetic marker resolution (i.e., barcode versus multilocus). However, the multilocus approach was more effective than the single barcode in detecting the presence of a heterogeneous Pool-Seq sample. These results suggest that presumed symbiont dispersal capabilities are not always strong indicators of host specificity or of historical host-symbiont coevolutionary events. Comprehensive sampling at fine phylogenetic scales may help to better elucidate the microevolutionary filters that impact macroevolutionary processes regulating symbioses, particularly for dispersal-limited symbionts.

Human Follicular Mites: Ectoparasites Becoming Symbionts

Article

Full-text available

Jun 2022

Most humans carry mites in the hair follicles of their skin for their entire lives. Follicular mites are the only metazoans tha continuously live on humans. We propose that Demodex folliculorum (Acari) represents a transitional stage from a host-injuring obligate parasite to an obligate symbiont. Here, we describe the profound impact of this transition on the genome and physiology of the mite. Genome sequencing revealed that the permanent host association of D. folliculorum led to an extensive genome reduction through relaxed selection and genetic drift, resulting in the smallest number of protein-coding genes yet identified among panarthropods. Confocal microscopy revealed that this gene loss coincided with an extreme reduction in the number of cells. Single uninucleate muscle cells are sufficient to operate each of the three segments that form each walking leg. While it has been assumed that the reduction of the cell number in parasites starts early in development, we identified a greater total number of cells in the last developmental stage (nymph) than in the terminal adult stage, suggesting that reduction starts at the adult or ultimate stage of development. This is the first evolutionary step in an arthropod species adopting a reductive, parasitic or endosymbiotic lifestyle. Somatic nuclei show underreplication at the diploid stage. Novel eye structures or photoreceptors as well as a unique human host melatonin-guided day/night rhythm are proposed for the first time. The loss of DNA repair genes coupled with extreme endogamy might have set this mite species on an evolutionary dead-end trajectory.

The ghost of hosts past: impacts of host extinction on parasite specificity

Preprint

May 2021

A growing body of research is focused on the extinction of parasite species in response to host endangerment and declines. Beyond the loss of parasite species richness, host extinction can impact apparent parasite host specificity, as measured by host richness or the phylogenetic distances among hosts. Such impacts on the distribution of parasites across the host phylogeny can have knock-on effects that may reshape the adaptation of both hosts and parasites, ultimately shifting the evolutionary landscape underlying the potential for emergence and the evolution of virulence across hosts. Here we examine how the reshaping of host phylogenies through extinction may impact the host specificity of parasites, and offer examples from historical extinctions, present-day endangerment, and future projections of biodiversity loss. We suggest that an improved understanding of the impact of host extinction on contemporary host-parasite interactions may shed light on core aspects of disease ecology, including comparative studies of host specificity, virulence evolution in multi-host parasite systems, and future trajectories for host and parasite biodiversity.

Host diversity outperforms climate as a global driver of symbiont diversity in the bird-feather mite system

Article

Full-text available

Nov 2020
DIVERS DISTRIB

Aim The simultaneous influence of abiotic and biotic factors as main drivers of global species distributions remains poorly understood, especially in host‐dependent groups. In this study, we diverge from traditional macroecological approaches by considering both biotic (avian species diversity) and abiotic (climatic) factors in determining the global distribution pattern of feather mite species richness, one of the most abundant and diverse bird ectosymbionts. Location Global. Methods We used a global dataset of feather mite–bird interactions published in 2016, complemented with an up‐to‐date literature survey. We created statistical models designed to explain the effect of abiotic (i.e., temperature, precipitation and energy‐related variables) and biotic factors (bird species richness) on the species richness of feather mites. We used these models to predict global distribution patterns of mites and estimate each explanatory variable's relative importance in temperate and tropical regions. Results According to our models, bird species richness accounts for ~63% of the global distribution pattern of mites, which is ten times more relevant than climatic variables. Among abiotic drivers, precipitation intensity and seasonality were the most important variables, accounting for 10% of mite species richness. This figure is lower in tropical regions, where biotic factors are seven times more important than in temperate regions. Main conclusions We demonstrate that global mite diversity was primarily determined by biotic and, to a lesser extent, abiotic factors. The relative importance of the predictive variables, however, varied between tropical and temperate regions. The strong association between bird species richness and feather mite species diversity at a global scale raises concerns about the potential for future co‐extinctions.

Ecological Niche Modeling and Other Tools for the Study of Avian Malaria Distribution in the Neotropics: A Short Literature Review

Chapter

Oct 2020

Identifying the mechanisms driving the distribution, diversity, and structure of parasite assemblages is critical to understand host–parasite evolution, community dynamics, and disease transmission risk. However, despite their global distribution, the broad-scale environmental factors that can affect avian haemosporidian transmission remain only partially understood across avian communities in the Neotropics. With the recent technological advances in satellite imagery, computer modeling, and molecular biology, we are now capable of studying infectious diseases in an integrated fashion over diverse spatial scales. From this perspective, ecological niche modeling (ENM) and species distribution modeling (SDM) represent useful tools to study vector-borne diseases, emphasizing the role of environmental factors in constraining their geographic distributions. Herein, we present a review of studies that have implemented modeling approaches, particularly correlative methods commonly used in ENM and SDM, to assess questions of either parasites, vectors, or host species in avian malaria. We identify that most commonly approached topics include the description of geographic distributions (biogeography), population demography, and structure of the host communities (ecology), and in low proportion, other important topics include climate change effects and potential risk for invasions. We observed that most studies were performed from local to regional scales and were concentrated mainly on vectors, followed by a combination of parasites and hosts. The correlative algorithm used was mainly Maxent; however, other statistical analyses included spatial regressions, smoothing procedures, and more conventional multivariate regressions developed chiefly on environmental dimensions. To date, applications of these approaches to the understanding of the geography and ecology of vector-borne diseases are in early stages. Diverse challenges related to theoretical and empirical advances, as well as the need for more (organized) data, still remain poorly explored. We present an adaptation of the Biotic-Abiotic-Mobility (BAM) framework to describe new potential arrangements in the context of this complex epidemiological/epizootiological systems. We hope this review can be useful to provide the basic knowledge and guidance for modeling of ecological niches on avian haemosporidian systems.

Inordinate Fondness Multiplied and Redistributed: the Number of Species on Earth and the New Pie of Life

Article

Full-text available

Sep 2017

The number of species on Earth is one of the most fundamental numbers in science, but one that remains highly uncertain. Clearly, more species exist than the present number of formally described species (approximately 1.5 million), but projected species numbers differ dramatically among studies. Recent estimates range from about 2 million species to approximately 1 trillion, but most project around 11 million species or fewer. Numerous studies have focused on insects as a major component of overall richness, and many have excluded other groups, especially non-eukaryotes. Here, we re-estimate global biodiversity. We also estimate the relative richness of the major clades of living organisms, summarized as a " Pie of Life. " Unlike many previous estimates, we incorporate morphologically cryptic arthropod species from molecular-based species delimitation. We also include numerous groups of organisms that have not been simultaneously included in previous estimates, especially those often associated with particular insect host species (including mites, nematodes, apicomplexan protists, microsporidian fungi, and bacteria). Our estimates suggest that there are likely to be at least 1 to 6 billion species on Earth. Furthermore, in contrast to previous estimates, the new Pie of Life is dominated by bacteria (approxi-mately 70–90% of species) and insects are only one of many hyperdiverse groups.

Detecting ancient co-dispersals and host shifts by double dating of host and parasite phylogenies: Application in proctophyllodid feather mites associated with passerine birds

Article

Full-text available

Jul 2017
EVOLUTION

Inferring co-phylogeographic events requires matching the timing of these events on both host and symbiont (e.g., parasites) phylogenies because divergences of hosts and their symbionts may not temporally coincide, and host switches may occur. We investigate a large radiation of birds (Passeriformes) and their permanent symbionts, the proctophyllodid feather mites (117 species from 116 bird species; 6 genes, 11,468 nt aligned) using two time-calibration strategies for mites: fossils only and host phylogeography only. Out of 10 putative co-phylogeographic events 4 agree in timing for both symbiont and host events being synchronous co-origins or co-dispersals; 3 were based on host shifts, but agree in timing being very close to the origin of modern hosts; 2 disagree; and 1 large basal mite split was seemingly independent from host phylogeography. Among these events was an ancient (21-25.3 Mya), synchronous co-dispersal from the Old World leading to the origin and diversifications of New World emberizoid passerids and their mites, the thraupis+quadratus species groups of Proctophyllodes. Our framework offers a more robust detection of host and symbiont co-phylogeographic events (as compared to host-symbiont reconciliation analysis and using host phylogeography for time-calibration) and provides independent data for testing alternative hypotheses on timing of host diversification and dispersal. This article is protected by copyright. All rights reserved

Feather mites: General morphological adaptations, phylogeny and coevolutionary relationships with birds

Article

Full-text available

Jan 1999

Sergey V. Mironov

Revisiting the particular role of host shifts in initiating insect speciation

Article

Full-text available

Jan 2017
EVOLUTION

The notion that shifts to new hosts can initiate insect speciation is more than 150 years old, yet widespread conflation with paradigms of sympatric speciation has led to confusion about how much support exists for this hypothesis. Here, we review 85 insect systems and evaluate the relationship between host shifting, reproductive isolation, and speciation. We sort insects into five categories: 1) systems in which a host shift has initiated speciation; 2) systems in which a host shift has made a contribution to speciation; 3) systems in which a host shift has caused the evolution of new reproductive isolating barriers; 4) systems with host-associated genetic differences; and 5) systems with no evidence of host-associated genetic differences. We find host-associated genetic structure in 65 systems, 43 of which show that host shifts have resulted in the evolution of new reproductive barriers. Twenty-six of the latter also support a role for host shifts in speciation, including eight studies that definitively support the hypothesis that a host shift has initiated speciation. While this review is agnostic as to the fraction of all insect speciation events to which host shifts have contributed, it clarifies that host shifts absolutely can and do initiate speciation. This article is protected by copyright. All rights reserved.

Geography and major host evolutionary transitions shape the resource use of plant parasites

Article

Full-text available

Aug 2016
P NATL ACAD SCI USA

Significance Patterns of host use by parasites are commonly thought to be limited by phylogenetic constraints, yet little is known about the role of the geographic distribution of hosts and parasites in such patterns. We show that evolutionary patterns in host use by a family of plant parasites are largely determined by the geographical distribution of hosts and parasites. Such phylogenetic lability in host use results in repeated colonizations of distantly related plant lineages, even across major plant evolutionary transitions. Still, these transitions constitute significant adaptive barriers in the evolution of host use. Our results thus show that host plant use by parasitic mites hinges more on where the plant and the mite are than on phylogenetic constraints.

In four shallow and mesophotic tropical reef sponges from Guam the microbial community largely depends on host identity

Article

Full-text available

May 2016

Sponges (phylum Porifera) are important members of almost all aquatic ecosystems, and are renowned for hosting often dense and diverse microbial communities. While the specificity of the sponge microbiota seems to be closely related to host phylogeny, the environmental factors that could shape differences within local sponge-specific communities remain less understood. On tropical coral reefs, sponge habitats can span from shallow areas to deeper, mesophotic sites. These habitats differ in terms of environmental factors such as light, temperature, and food availability, as well as anthropogenic impact. In order to study the host specificity and potential influence of varying habitats on the sponge microbiota within a local area, four tropical reef sponges, Rhabdastrella globostellata , Callyspongia sp., Rhaphoxya sp., and Acanthella cavernosa , were collected from exposed shallow reef slopes and a deep reef drop-off. Based on 16S rRNA gene pyrosequencing profiles, beta diversity analyses revealed that each sponge species possessed a specific microbiota that was significantly different to those of the other species and exhibited attributes that are characteristic of high- and/or low-microbial-abundance sponges. These findings emphasize the influence of host identity on the associated microbiota. Dominant sponge- and seawater-associated bacterial phyla were Chloroflexi, Cyanobacteria, and Proteobacteria. Comparison of individual sponge taxa and seawater samples between shallow and deep reef sites revealed no significant variation in alpha diversity estimates, while differences in microbial beta diversity (variation in community composition) were significant for Callyspongia sp. sponges and seawater samples. Overall, the sponge-associated microbiota is significantly shaped by host identity across all samples, while the effect of habitat differentiation seems to be less predominant in tropical reef sponges.

Niche Partitioning of Feather Mites within a Seabird Host, Calonectris borealis

Article

Full-text available

Dec 2015
PLOS ONE

According to classic niche theory, species can coexist in heterogeneous environments by reducing interspecific competition via niche partitioning, e.g. trophic or spatial partitioning. However, support for the role of competition on niche partitioning remains controversial. Here, we tested for spatial and trophic partitioning in feather mites, a diverse and abundant group of arthropods. We focused on the two dominant mite species, Microspalax brevipes and Zachvatkinia ovata, inhabiting flight feathers of the Cory's shearwater, Calonectris borealis. We performed mite counts across and within primary and tail feathers on free-living shearwaters breeding on an oceanic island (Gran Canaria, Canary Islands). We then investigated trophic relationships between the two mite species and the host using stable isotope analyses of carbon and nitrogen on mite tissues and potential host food sources. The distribution of the two mite species showed clear spatial segregation among feathers; M. brevipes showed high preference for the central wing primary feathers, whereas Z. ovata was restricted to the two outermost primaries. Morphological differences between M. brevipes and Z. ovata support an adaptive basis for the spatial segregation of the two mite species. However, the two mites overlap in some central primaries and statistical modeling showed that Z. ovata tends to outcompete M. brevipes. Isotopic analyses indicated similar isotopic values for the two mite species and a strong correlation in carbon signatures between mites inhabiting the same individual host suggesting that diet is mainly based on shared host-associated resources. Among the four candidate tissues examined (blood, feather remains, skin remains and preen gland oil), we conclude that the diet is most likely dominated by preen gland oil, while the contribution of exogenous material to mite diets is less marked. Our results indicate that ongoing competition for space and resources plays a central role in structuring feather mite communities. They also illustrate that symbiotic infracommunities are excellent model systems to study trophic ecology, and can improve our understanding of mechanisms of niche differentiation and species coexistence.

A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing

Article

Full-text available

Oct 2015
NATURE

Although reconstruction of the phylogeny of living birds has progressed tremendously in the last decade, the evolutionary history of Neoaves-a clade that encompasses nearly all living bird species-remains the greatest unresolved challenge in dinosaur systematics. Here we investigate avian phylogeny with an unprecedented scale of data: >390,000 bases of genomic sequence data from each of 198 species of living birds, representing all major avian lineages, and two crocodilian outgroups. Sequence data were collected using anchored hybrid enrichment, yielding 259 nuclear loci with an average length of 1,523 bases for a total data set of over 7.8 × 10(7) bases. Bayesian and maximum likelihood analyses yielded highly supported and nearly identical phylogenetic trees for all major avian lineages. Five major clades form successive sister groups to the rest of Neoaves: (1) a clade including nightjars, other caprimulgiforms, swifts, and hummingbirds; (2) a clade uniting cuckoos, bustards, and turacos with pigeons, mesites, and sandgrouse; (3) cranes and their relatives; (4) a comprehensive waterbird clade, including all diving, wading, and shorebirds; and (5) a comprehensive landbird clade with the enigmatic hoatzin (Opisthocomus hoazin) as the sister group to the rest. Neither of the two main, recently proposed Neoavian clades-Columbea and Passerea-were supported as monophyletic. The results of our divergence time analyses are congruent with the palaeontological record, supporting a major radiation of crown birds in the wake of the Cretaceous-Palaeogene (K-Pg) mass extinction.

Understanding Host-Switching by Ecological Fitting

Article

Full-text available

Oct 2015
PLOS ONE

Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process.

Evolution in Action: Climate Change, Biodiversity Dynamics and Emerging Infectious Disease

Article

Full-text available

Apr 2015
PHILOS T R SOC B

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host-parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly observable in real time. The emerging Stockholm Paradigm resolves this paradox: Ecological Fitting (EF)-phenotypic flexibility and phylogenetic conservatism in traits related to resource use, most notably host preference-provides many opportunities for rapid host switching in changing environments, without the evolution of novel host-utilization capabilities. Host shifts via EF fuel the expansion phase of the Oscillation Hypothesis of host range and speciation and, more generally, the generation of novel combinations of interacting species within the Geographic Mosaic Theory of Coevolution. In synergy, an environmental dynamic of Taxon Pulses establishes an episodic context for host and geographical colonization. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

(macro-) Evolutionary ecology of parasite diversity: From determinants of parasite species richness to host diversification

Article

Full-text available

Jan 2015

Serge Morand

The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

Differences in speciation progress in feather mites (Analgoidea) inhabiting the same host: the case of Zachvatkinia and Alloptes living on arctic and long- tailed skuas

Article

Full-text available

Oct 2014
EXP APPL ACAROL

Recent molecular phylogenetic analyses have revealed that some apparently oligoxenous feather mite species are in fact monoxenous cryptic species with little morphological differentiation. In this study we analyzed two species, Zachvatkinia isolata (Avenzoariidae) and Alloptes (Sternalloptes) stercorarii (Alloptidae) which prefer different parts of the plumage of two sister species of birds: arctic skua (Stercorarius parasiticus) and long-tailed skua (S. longicaudus) breeding on tundra in the High Arctic archipelago of Svalbard. Given that there are no reports about hybridization events between the host species, we expected that both skuas would have a species-specific acarofauna. The genetic distances among DNA-barcode sequences (COI and 28S rDNA), phylogenetic tree topologies, and haplotype networks of the COI sequences of mites suggested extensive gene flow in Z. isolata between and within populations inhabiting both skua species, whereas the Alloptes populations were host specific and sufficiently genetically separated as to warrant species-level status. The discrepancy in the genetic structure of Alloptes and Zachvatkinia populations suggests frequent but transient contacts between the two skua species in which the probability of mite exchange is much higher for Zachvatkinia, which is present in high numbers and inhabits exposed parts of primary flight feathers, than for the less abundant Alloptes that lives primarily in more protected and inaccessible parts of the plumage. We discuss the possible nature of these contacts between host species and the area(s) where they might take place. The star-like structures in the haplotype network as well as high haplotype diversity and low nucleotide diversity observed in Z. isolata are concordant with the known dispersal strategy of feather mites: vertical colonization of new host individuals followed by rapid growth of founder populations.

Host generalists and specialists emerging side by side: An analysis of evolutionary patterns in the cosmopolitan chewing louse genus Menacanthus

Article

Full-text available

Jan 2015
Int J Parasitol

Parasites with wide host spectra provide opportunities to study the ecological parameters of speciation, as well as the process of the evolution of host specificity. The speciose and cosmopolitan louse genus Menacanthus comprises both multi-host and specialised species, allowing exploration of the ecological and historical factors affecting the evolution of parasites using a comparative approach. We used phylogenetic analysis to reconstruct evolutionary relationships in 14 species of Menacanthus based on the sequences of one mitochondrial and one nuclear gene. The results allowed us to validate species identification based on morphology, as well as to explore host distribution by assumed generalist and specialist species. Our analyses confirmed a narrow host use for several species, however in some cases, the supposed host specialists had a wider host spectrum than anticipated. In one case a host generalist (Menacanthuseurysternus) was clustered terminally on a clade almost exclusively containing host specialists. Such a clade topology indicates that the process of host specialisation may not be irreversible in parasite evolution. Finally, we compared patterns of population genetic structure, geographic distribution and host spectra between two selected species, M. eurysternus and Menacanthus camelinus, using haplotype networks. Menacanthus camelinus showed limited geographical distribution in combination with monoxenous host use, whereas M. eurysternus showed a global distribution and lack of host specificity. It is suggested that frequent host switching maintains gene flow between M. eurysternus populations on unrelated hosts in local populations. However, gene flow between geographically distant localities was restricted, suggesting that geography rather than host-specificity is the main factor defining the global genetic diversity of M. eurysternus.

Drivers of parasite sharing among Neotropical freshwater fishes

Article

Full-text available

Oct 2014
J ANIM ECOL

Because host–parasite interactions are so ubiquitous, it is of primary interest for ecologists to understand the factors that generate, maintain and constrain these associations. Phylogenetic comparative studies have found abundant evidence for host‐switching to relatively unrelated hosts, sometimes related to diversification events, in a variety of host–parasite systems. For Monogenoidea (Platyhelminthes) parasites, it has been suggested that the co‐speciation model alone cannot explain host occurrences, hence host‐switching and/or non‐vicariant modes of speciation should be associated with the origins and diversification of several monogenoid taxa. The factors that shape broad patterns of parasite sharing were investigated using path analysis as a way to generate hypotheses about the origins of host–parasite interactions between monogenoid gill parasites and Neotropical freshwater fishes. Parasite sharing was assessed from an interaction matrix, and explanatory variables included phylogenetic relationships, environmental preferences, biological traits and geographic distribution for each host species. Although geographic distribution of hosts and host ecology are important factors to understand host–parasite interactions, especially within host lineages that share a relatively recent evolutionary history, phylogeny had the strongest overall direct effect on parasite sharing. Phylogenetic contiguity of host communities may allow a ‘stepping‐stone’ mode of host‐switching, which increases parasite sharing. Our results reinforce the importance of including evolutionary history in the study of ecological associations, including emerging infectious diseases risk assessment.

Species formation by host shifting in avian malaria parasites

Article

Full-text available

Oct 2014
P NATL ACAD SCI USA

Significance Emerging infectious diseases pose threats to humans and livestock, but little is known about the general propensity of parasitic organisms to shift between hosts or the role of host shifting in the diversification of parasite lineages. The malaria parasites of contemporary vertebrate species descended from a common ancestor, likely after the diversification of their major host taxa, requiring rapid speciation and shifting between hosts across large host–taxonomic distances. Examination of sister lineages of avian malaria parasites in the New World suggests that such host shifting is common and often leads to the origin of new evolutionary lineages of parasites.

Repeatability of Feather Mite Prevalence and Intensity in Passerine Birds

Article

Full-text available

Sep 2014
PLOS ONE

Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (Radj) after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity). The prevalence of feather mites was moderately repeatable (R = 0.26–0.53; Radj = 0.32–0.57); smaller values were found for intensity (R = 0.19–0.30; Radj = 0.18–0.30). These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity.

From cuckoos to chickens: a caught-in-the-act case of host shift in feather mites (Arachnida: Acari: Psoroptoididae)

Article

Full-text available

Sep 2014

Feather mites are highly specialized permanent ectosymbionts recorded from all recently recognized bird orders. These mites, specialized to live in the plumage of their hosts, rarely cause any visible damage to their specific hosts. Recently described feather mite Allopsoroptoides galli Mironov (Acariformes: Psoroptoididae) was reported to cause severe mange in chickens in Brazil, leading to unprecedented economic losses. Until now, the natural host of A. galli remained unknown. In this paper, we report its true wild host, the Guira cuckoo Guira guira (Cuculiformes: Cuculidae). In addition, a previously unknown heteromorphic form of males is described from the mite population distributed on its natural host. We also speculate a possible scenario by which this mite species could have been horizontally transferred from the wild populations of the natural host to the secondary hosts.

Avibase - A database system for managing and organizing taxonomic concepts

Article

Full-text available

Jun 2014

Scientific names of biological entities offer an imperfect resolution of the concepts that they are intended to represent. Often they are labels applied to entities ranging from entire populations to individual specimens representing those populations, even though such names only unambiguously identify the type specimen to which they were originally attached. Thus the real-life referents of names are constantly changing as biological circumscriptions are redefined and thereby alter the sets of individuals bearing those names. This problem is compounded by other characteristics of names that make them ambiguous identifiers of biological concepts, including emendations, homonymy and synonymy. Taxonomic concepts have been proposed as a way to address issues related to scientific names, but they have yet to receive broad recognition or implementation. Some efforts have been made towards building systems that address these issues by cataloguing and organizing taxonomic concepts, but most are still in conceptual or proof-of-concept stage. We present the on-line database Avibase as one possible approach to organizing taxonomic concepts. Avibase has been successfully used to describe and organize 844,000 species-level and 705,000 subspecies-level taxonomic concepts across every major bird taxonomic checklist of the last 125 years. The use of taxonomic concepts in place of scientific names, coupled with efficient resolution services, is a major step toward addressing some of the main deficiencies in the current practices of scientific name dissemination and use.

How Specialists Can Be Generalists: Resolving the "Parasite Paradox" and Implications for Emerging Infectious Disease

Article

Full-text available

Apr 2010

The parasite paradox arises from the dual observations that parasites (broadly construed, including phytophagous insects) are resource specialists with restricted host ranges, and yet shifts onto relatively unrelated hosts are common in the phylogenetic diversification of parasite lineages and directly observable in ecological time. We synthesize the emerging solution to this paradox: phenotypic flexibility and phylogenetic conservatism in traits related to resource use, grouped under the term ecological fitting, provide substantial opportunities for rapid host switching in changing environments, in the absence of the evolution of novel host-utilization capabilities. We discuss mechanisms behind ecological fitting, its implications for defining specialists and generalists, and briefly review empirical examples of host shifts in the context of ecological fitting. We conclude that host shifts via ecological fitting provide the fuel for the expansion phase of the recently proposed oscillation hypothesis of host range and speciation, and, more generally, the generation of novel combinations of interacting species within the geographic mosaic theory of coevolution. Finally, we conclude that taxon pulses, driven by climate change and large-scale ecological perturbation are drivers of biotic mixing and resultant ecological fitting, which leads to increased rates of rapid host switching, including the agents of Emerging Infectious Disease.

Evolution of host-parasite associations among species of lice and rock-wallabies: Coevolution? Int. J

Article

Full-text available

Stephen Charles Barker

Ehrlich and Raven Revisited: Mechanisms Underlying Codiversification of Plants and Enemies

Article

Full-text available

Nov 2011

Niklas Janz

After almost 50 years of scrutiny, the ideas that Ehrlich and Raven presented in their classical paper on the coevolution between butterflies and plants are still very much alive. Much of this interest has involved the potential for codiversification, both in how the interaction itself diversifies and how the interaction affects modes and rates of speciation. Despite high levels of conservatism and specialization, diversification of the interaction appears to be mainly a consequence of host shifts, but this somewhat paradoxical conclusion can be understood by an appreciation of the ecological as well as genetic mechanisms behind host shifts. There are several ways that the interaction can influence speciation, with or without host-plant-based divergent selection on reproductive barriers. One current debate is over the relative importance of radiations following shifts to new adaptive zones and elevated rates of speciation in groups with plastic and diverse host use.

Feather mites (Astigmata; Pterolichoidea, Analgoidea) and birds as models for cophylogenetic studies

Article

Full-text available

Jan 2005

Jacek Dabert

Particular taxa of feather mites (Astigmata; Analgoidea, Pterolichoidea) are associated with particular taxa of their bird hosts, suggesting a general coevolutionary pattern of phylogenies for the two animal groups.This assumption is supported by observations of specific and sometimes bizarre morphological mite adaptations to living in bird plumage and by general high host specificity.The paper summarizes recent knowledge of the evolutionary processes involved in the origin of host-parasite relationships of feather mites and birds. A theoretical and methodological back-ground to cophylogenetic studies is briefly discussed. Some striking examples of cospeciation between feather mites and their hosts are presented. However, other co-phylogenetic events (e.g. duplications, sorting events, host switching) may greatly complicate the pattern of the host-parasite relationships. Some clear examples of non-parallel evolutionary processes (e.g.the mite distribution better correlated with geography than with host phylogeny) in the origin of particular feather mite acarofaunas are shown.The phylogenetic information of feather mites is suggested as an additional tool for testing alternative hypotheses concerning problematic issues in bird phylogeny.

Phylogeny of feather mites of the subfamily Pterodectinae (Acariformes: Proctophyllodidae) and their host associations with passerines (Passeriformes)

Article

Jun 2009

Sergey V. Mironov

A phylogenetic hypothesis of the feather mite subfamily Pterodectinae Park et Atyeo, 1971 (Astigmata: Proctophyllodidae), currently including 165 species in 19 genera, was constructed by means of the maximum parsimony approach. It is shown that the proctophyllodid mites characterized by the epigynum fused to epimerites in females and by the absence of terminal membranous extensions of the opisthosoma in males that were arranged by previous authors into two subfamilies, Pterodectinae and Rhamphocaulinae, constitute a common phylogenetic branch within Proctophyllodidae. It is proposed to threat this whole branch as the subfamily Pterodectinae. The subfamily Pterodectinae in the new sense consists of two branches, which are treated as the tribes Pterodectini trib. nov. and Rhamphocaulini Park et Atyeo, 1971 stat. nov. The generic contents of these tribes are rearranged comparing to those in Pterodectinae and Rhamphocaulinae of previous authors. A preliminary hypothesis about the origin and dispersion of Pterodectinae on passerine hosts is proposed. It is suggested that this subfamily originated on the ancestors of Passeriformes. The origin and subsequent diversification of two major phylogenetic branches (Pterodectini and Rhamphocaulini) was related with two main taxonomic grouping of avian hosts, passerines and hummingbirds (Apodiformes: Trochilidae), respectively; although on the latter hosts they are of secondary origin. The phylogeny, host associations and geographic distribution of pterodectines predominately associated with passerines generally correspond to the phylogeny and historical biogeography of the order Passeriformes. The current distribution of pterodectines among passerines was realized by cospeciation with their hosts, and also by numerous cases of switching to new host taxa, mainly within Passeriformes, but also to bird of other orders. Nanopterodectes nom. nov. is proposed for the pterodectine genus Nanodectes Mironov in Mironov et al. 2008b (Acariformes: Proctophyllodidae), which was preoccupied (Rentz 1985; Orthoptera: Tettigoniidae); the sole species of this genus gets a new name Nanopterodectes formicivorae (Mironov, 2008) comb. nov.

Partitioning the turnover and nestedness components of beta diversity: Partitioning beta diversity

Article

Oct 2009

Andrés Baselga

Coevolution of Life on Hosts: Integrating Ecology and History

Book

Nov 2016

Cophylogenetic analyses reveal extensive host-shift speciation in a highly specialized and host-specific symbiont system

Article

Aug 2017

Vertical transmission in feather mites: Insights into its adaptive value

Article

Apr 2017

1. The consequences of symbiont transmission strategies are better understood than their adaptive causes. 2. Feather mites are permanent ectosymbionts of birds assumed to be transmitted mainly vertically from parents to offspring. The transmission of Proctophyllodes doleophyes G aud ( A stigmata, P roctophyllodidae) was studied in two E uropean populations of pied flycatchers, Ficedula hypoleuca P allas ( P asseriformes, M uscicapidae). 3. The vertical transmission of this mite species is demonstrated here with an acaricide experiment. This study also compared (for two distant populations during 4 years) patterns in reductions in mite intensity in adult birds, from egg incubation to chick‐rearing periods, with the predictions of three hypotheses on how host survival prospects and mite intraspecific competition might drive feather mites' transmission strategy. 4. The results are in agreement with previous studies and show that feather mites transmit massively from parents to chicks. 5. The magnitude of the transmission was closer to that predicted by the hypothesis based on intraspecific competition, while a bet‐hedging strategy is also partially supported.

A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing

Article

Jul 2016

Although reconstruction of the phylogeny of living birds has progressed tremendously in the last decade, the evolutionary history of Neoaves—a clade that encompasses nearly all living bird species—remains the greatest unresolved challenge in dinosaur systematics. Here we investigate avian phylogeny with an unprecedented scale of data: >390,000 bases of genomic sequence data from each of 198 species of living birds, representing all major avian lineages, and two crocodilian outgroups. Sequence data were collected using anchored hybrid enrichment, yielding 259 nuclear loci with an average length of 1,523 bases for a total data set of over 7.8 × 10⁷ bases. Bayesian and maximum likelihood analyses yielded highly supported and nearly identical phylogenetic trees for all major avian lineages. Five major clades form successive sister groups to the rest of Neoaves: (1) a clade including nightjars, other caprimulgiforms, swifts, and hummingbirds; (2) a clade uniting cuckoos, bustards, and turacos with pigeons, mesites, and sandgrouse; (3) cranes and their relatives; (4) a comprehensive waterbird clade, including all diving, wading, and shorebirds; and (5) a comprehensive landbird clade with the enigmatic hoatzin (Opisthocomus hoazin) as the sister group to the rest. Neither of the two main, recently proposed Neoavian clades—Columbea and Passerea—were supported as monophyletic. The results of our divergence time analyses are congruent with the palaeontological record, supporting a major radiation of crown birds in the wake of the Cretaceous–Palaeogene (K–Pg) mass extinction.

Animals as Habitats

Chapter

Jul 2013

To most non-biologists, a ‘mite’ is an almost invisible creature that lives in the carpet and gives you asthma or that burrows in your skin to produce socially unacceptable scabies. Cat owners may curse the ear mites that infest their pets and those who know that ticks are mites may mention Lyme Disease. Such medically important associations between mites and mammals are discussed in most parasitology texts, and mites associated with human diseases are discussed in our Chap. 10; therefore, in this chapter we cover ticks and other human- and livestock-associated mites superficially, concentrating instead on lesser known relationships between mites and the animals they use for room and board. These associations are not always negative; in fact, many seemingly parasitic mites have no impact on their hosts or may even be beneficial (see section “Mutualism”, below) (Fig. 9.1).

Ectoparasitic "Jacks-of-All-Trades": Relationship between Abundance and Host Specificity in Fleas (Siphonaptera) Parasitic on Small Mammals

Article

Oct 2004

Animal species with larger local populations tend to be widespread across many localities, whereas species with smaller local populations occur in fewer localities. This pattern is well documented for free‐living species and can be explained by the resource breadth hypothesis: the attributes that enable a species to exploit a diversity of resources allow it to attain a broad distribution and high local density. In contrast, for parasitic organisms, the trade‐off hypothesis predicts that parasites exploiting many host species will achieve lower mean abundance on those hosts than more host‐specific parasites because of the costs of adaptations against multiple defense systems. We test these alternative hypotheses with data on host specificity and abundance of fleas parasitic on small mammals from 20 different regions. Our analyses controlled for phylogenetic influences, differences in host body surface area, and sampling effort. In most regions, we found significant positive relationships between flea abundance and either the number of host species they exploited or the average taxonomic distance among those host species. This was true whether we used mean flea abundance or the maximum abundance they achieved on their optimal host. Although fleas tended to exploit more host species in regions with either larger number of available hosts or more taxonomically diverse host faunas, differences in host faunas between regions had no clear effect on the abundance–host specificity relationship. Overall, the results support the resource breadth hypothesis: fleas exploiting many host species or taxonomically unrelated hosts achieve higher abundance than specialist fleas. We conclude that generalist parasites achieve higher abundance because of a combination of resource availability and stability.

Global associations between birds and vane-dwelling feather mites

Article

Oct 2016

Understanding host–symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird–feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used.

When do parasites fail to speciate in response to host speciation?

Article

Feb 2003

Cospeciation generally increases the similarity between host and parasite phylogenies. Incongruence between host and parasite phylogenies has previously been explained in terms of host switching, sorting, and duplication events. Here, we describe an additional process, failure of the parasite to speciate in response to host speciation, that may be important in some host-parasite systems. Failure to speciate is likely to occur when gene flow among parasite populations is much higher than that of their hosts. We reconstructed trees from mitochondrial and nuclear DNA sequences for pigeons and doves (Aves: Columbiformes) and their feather lice in the genus Columbicola (Insecta: Phthiraptera). Although comparisons of the trees from each group revealed a significant amount of cospeciation, there was also a significant degree of incongruence. Cophylogenetic analyses generally indicated that host switching may be an important process in the history of this host-parasite association. Using terminal sister taxon comparisons, we also identified three apparent cases where the host has speciated but the associated parasite has not. In two of these cases of failure to speciate, these comparisons involve allopatric sister taxa of hosts whose lice also occur on hosts sympatric with both of the allopatric sisters. These additional hosts for generalist lice may promote gene flow with lice on the allopatric sister species. Relative rate comparisons for the mitochondrial cytochrome oxidase I gene indicate that molecular substitution occurs about 11 times faster in lice than in their avian hosts.

Package 'betapart': Partitioning beta diversity into turnover and nestedness components

Technical Report

Dec 2013

New feather mites of the subfamily Pterodectinae (Acariformes: Proctophyllodidae) from passerines (Aves: Passeriformes) from Chile and Cuba

Article

Oct 2011
ZOOTAXA

Ten new species of the feather mite subfamily Pterodectinae (Analgoidea: Proctophyllodidae) are described from New World passeriforms collected in Chile and Cuba: Amerodectes caribaeus sp. n. from Contopus caribaeus (Linnaeus) (Tyrannidae), A. contopus sp. n. from C. virens (Linnaeus) (Tyrannidae), A. plumbeus sp. n. from Turdus plumbeus Linnaues (Turdidae), A. phrygilus sp. n. from Phrygilus patagonicus Lowe (Emberizidae), A. sicalis sp. n. from Sicalis luteola (Sparman) (Emberizidae), A. wilsoniae sp. n. from Wilsonia citrina (Boddaert) (Parulidae), Metapterodectes leptasthenurae sp. n. from Leptasthenura aegithaloides (Kittlitz) (Furnariidae), Tyrannidectes anairetes sp. n. from Anairetes parulus (Kittlitz) (Tyrannidae), T. cinclodes sp. n. from Cinclodes patagonicus (Gmelin) (Furnariidae), T. f a l - cklandicus sp. n. from Turdus falcklandii Quoy and Gaimard (Turdidae). Keys to all currently described species of the genera Amerodectes Valim and Hernandes, 2010, Metapterodectes Mironov, 2008, and Tyrannidectes Mironov, 2008 and improved diagnoses of these genera are proposed. Brief comments on the suprageneric systematics of the family Proctophyllodidae are given.

A new method for non-parametric multivariate analysis of variance

Article

Jan 2001

Marti J. Anderson

Evolution of parasite life cycles in parasite-host associations

Article

Jan 1991

C. Combes

Using the BirdTree.org website to obtain robust phylogenies for avian comparative studies: A primer

Article

Dec 2015

Comparative studies of trait evolution require accounting for the shared evolutionary history. This is done by including phylogenetic hypotheses into statistical analyses of species’ traits, for which birds often serve as excellent models. The online publication of the most complete molecular phylogeny of extant bird species (www.birdtree.org, BirdTree hereafter) now allows evolutionary biologists to rapidly obtain sets of equally plausible phylogenetic trees for any set of species to be incorporated as a phylogenetic hypothesis in comparative analyses. We discuss methods to use BirdTree tree sets for comparative studies, either by building a consensus tree that can be incorporated into standard comparative analyses, or by using tree sets to account for the ef- fect of phylogenetic uncertainty. Methods accounting for phylogenetic uncertainty should be preferred whenever possible because they should provide more reliable parameter estimates and realistic confidence intervals around them. Based on a real compara- tive dataset, we ran simulations to investigate the effect of variation in the size of the random tree sets downloaded from BirdTree on the variability of parameter estimates from a bivariate relationship between mass-specific productivity and body mass. Irre- spective of the method of analysis, using at least 1,000 trees allows obtaining parameter estimates with very small (< 0.15%) co- efficients of variation. We argue that BirdTree, due to the ease of use and the major advantages over previous ‘traditional’ meth- ods to obtain phylogenetic hypotheses of bird species (e.g. supertrees or manual coding of published phylogenies), will become the standard reference in avian comparative studies for years to come.

Feather mites (Analgesoidea). Part I. Introduction to their study

Article

Jan 1951

V.B. Dubinin

Different space preferences and within-host competition promote niche partitioning between symbiotic feather mite species

Article

May 2015

Obligate symbionts (including parasites, commensals and mutualists) often share host species and host-based food resources. Such symbionts are frequently distributed unequally among hosts with different phenotypic features, or occupy different regions on a host. However, the processes leading to distinct within-host symbiont distributions remain obscure. We aimed to test whether distinct in-host symbiont distributions arise as the outcome of species-specific habitat preferences or interspecific competition, and how host phenotype influences such processes. To this end, we studied the distribution within and among individual bird hosts of two feather mites (Proctophyllodes sylviae and Trouessartia bifurcata) of migratory and sedentary European blackcaps, Sylvia atricapilla, wintering in sympatry. Trouessartia bifurcata was mostly restricted to resident blackcaps, while P. sylviae was abundant on both host types. Within hosts, each species tended to settle on different feather sectors (proximal or distal, respectively), which they filled by spreading on the wing following ordered but opposite patterns, thereby supporting the view that spatial segregation was primarily the outcome of dissimilar space preferences. However, we also found evidence of competition finely tuning mite distributions: when P. sylviae increased abundance and expanded onto the range of T. bifurcata, abundances of the two species were negatively correlated in the shared areas. In addition, the presence of T. bifurcata on a host was associated with a more restricted distribution of P. sylviae. Our results show that both species-specific preferences and interspecific interactions contribute to shaping mite distributions among and on individual hosts, a situation likely mirrored by other host-multi-symbiont systems. Copyright © 2015. Published by Elsevier Ltd.

Dispersal and ecological traits explain differences in beta diversity patterns of European beetles

Article

Apr 2015
J BIOGEOGR

Aim Disentangling the contributions of niche and dispersal processes as species distribution drivers is crucial from both theoretical and practical standpoints. We investigated whether niche‐related and dispersal‐related functional traits of 19 beetle clades were good predictors of beta diversity patterns across continental European countries. Location Continental Europe. Methods We quantified the overall compositional heterogeneity (a measure of multiple‐site dissimilarity) of each beetle clade in continental Europe and assessed its relationship with body size and the proportion of wingless species as proxies for dispersal ability. Overall compositional heterogeneity was also compared with trophic and habitat preferences of clades as proxies for their ecological specialization. Additionally, beta diversity patterns were characterized as a multivariate pairwise dissimilarity matrix among pairs of countries for each beetle clade. We assessed whether differences among these pairwise structures were related to dispersal ability or the ecological specialization of clades. The turnover and nestedness‐resultant components of compositional dissimilarity were calculated separately for all analyses. Results The dispersal ability and ecological specialization explained a large proportion (> 70%) of the variation in overall compositional heterogeneity but a lower proportion ( c . 40%) of the variation in the multivariate pairwise structures. Remarkably, the explained variation was shared between both sets of predictors in the case of overall compositional heterogeneity but was independently related to dispersal ability or ecological specialization for the multivariate pairwise structure analysis. Main conclusions These results suggest a tight relationship between ecological specialization, dispersal ability and compositional heterogeneity of European beetle clades. However, the specific patterns of dissimilarities between pairs of countries seem to be determined independently by either ecological or dispersal processes and seem to be subject to other unmeasured factors.

PERMANOVA, ANOSIM, and the Mantel test in the face of heterogeneous dispersions: What null hypothesis are you testing?

Article

Nov 2013

ANOSIM, PERMANOVA, and the Mantel test are all resemblance‐based permutation methods widely used in ecology. Here, we report the results of the first simulation study, to our knowledge, specifically designed to examine the effects of heterogeneity of multivariate dispersions on the rejection rates of these tests and on a classical MANOVA test (Pillai's trace). Increasing differences in dispersion among groups were simulated under scenarios of changing sample sizes, correlation structures, error distributions, numbers of variables, and numbers of groups for balanced and unbalanced one‐way designs. The power of these tests to detect environmental impacts or natural large‐scale biogeographic gradients was also compared empirically under simulations based on parameters derived from real ecological data sets. Overall, ANOSIM and the Mantel test were very sensitive to heterogeneity in dispersions, with ANOSIM generally being more sensitive than the Mantel test. In contrast, PERMANOVA and Pillai's trace were largely unaffected by heterogeneity for balanced designs. PERMANOVA was also unaffected by differences in correlation structure, unlike Pillai's trace. For unbalanced designs, however, all of the tests were (1) too liberal when the smaller group had greater dispersion and (2) overly conservative when the larger group had greater dispersion, especially ANOSIM and the Mantel test. For simulations based on real ecological data sets, PERMANOVA was generally, but not always, more powerful than the others to detect changes in community structure, and the Mantel test was usually more powerful than ANOSIM. Both the error distributions and the resemblance measure affected results concerning power. Differences in the underlying construction of these test statistics result in important differences in the nature of the null hypothesis they are testing, their sensitivity to heterogeneity, and their power to detect important changes in ecological communities. For balanced designs, PERMANOVA and PERMDISP can be used to rigorously identify location vs. dispersion effects, respectively, in the space of the chosen resemblance measure. ANOSIM and the Mantel test can be used as more “omnibus” tests, being sensitive to differences in location, dispersion or correlation structure among groups. Unfortunately, none of the tests (PERMANOVA, Mantel, or ANOSIM) behaved reliably for unbalanced designs in the face of heterogeneity.

Team RDC.R: A Language And Environment For Statistical Computing. R Foundation for Statistical Computing: Vienna, Austria

Technical Report

Jan 2012

Core R Team

DNA barcoding and mini-barcoding as a powerful tool for feather mite studies

Article

Feb 2015
MOL ECOL RESOUR

Feather mites (Astigmata: Analgoidea, Pterolichoidea) are among the most abundantand commonly occurring bird ectosymbionts. Basic questions on the ecology and evolution of feather mites remain unanswered because feather mite species identification is often only possible for adult males and it is laborious even for specialised taxonomists, thus precluding large-scale identifications. Here, we tested DNA barcoding as a useful molecular tool to identify feather mites from passerine birds. 361 specimens of 72 species of feather mites from 68 species of European passerine birds from Russia and Spain were barcoded. The accuracy of barcoding and mini-barcoding was tested. Moreover, threshold choice (a controversial issue in barcoding studies) was also explored in a new way, by calculating through simulations the effect of sampling effort (in species number and species composition) on threshold calculations. We found one 200 bp mini-barcode region that showed the same accuracy as the full-length barcode (602 bp) and was surrounded by conserved regions potentially useful for group-specific degenerate primers. Species identification accuracy was perfect (100%) but decreased when singletons or species of the Proctophyllodes pinnatus group were included. In fact, barcoding confirmed previous taxonomic issues within the Proctophyllodes pinnatus group. Following an integrative taxonomy approach, we compared our barcode study with previous taxonomic knowledge on feather mites, discovering three new putative cryptic species and validating three previous morphologically different (but still undescribed) new species.

DIVERSITREE: comparative phylogenetic analyses of diversification in R

Article

Dec 2012
Methods Ecol. Evol.

Richard G FitzJohn

1. The R package ‘diversitree’ contains a number of classical and contemporary comparative phylogenetic methods. Key included methods are BiSSE (binary state speciation and extinction), MuSSE (a multistate extension of BiSSE), and QuaSSE (quantitative state speciation and extinction). Diversitree also includes methods for analysing trait evolution and estimating speciation/extinction rates independently. 2. In this note, I describe the features and demonstrate use of the package, using a new method, MuSSE (multistate speciation and extinction), to examine the joint effects of two traits on speciation. 3. Using simulations, I found that MuSSE could reliably detect that a binary trait that affected speciation rates when simultaneously accounting for additional thats that had no effect on speciation rates. 4. Diversitree is an open source and available on the Comprehensive R Archive Network (cran). A tutorial and worked examples can be downloaded from http://www.zoology.ubc.ca/prog/diversitree.

Cospeciation vs host-shift speciation: Methods for testing, evidence from natural associations and relation to coevolution

Article

Feb 2013
NEW PHYTOL

Hosts and their symbionts are involved in intimate physiological and ecological interactions. The impact of these interactions on the evolution of each partner depends on the time‐scale considered. Short‐term dynamics – ‘coevolution’ in the narrow sense – has been reviewed elsewhere. We focus here on the long‐term evolutionary dynamics of cospeciation and speciation following host shifts. Whether hosts and their symbionts speciate in parallel, by cospeciation, or through host shifts, is a key issue in host–symbiont evolution. In this review, we first outline approaches to compare divergence between pairwise associated groups of species, their advantages and pitfalls. We then consider recent insights into the long‐term evolution of host–parasite and host–mutualist associations by critically reviewing the literature. We show that convincing cases of cospeciation are rare (7%) and that cophylogenetic methods overestimate the occurrence of such events. Finally, we examine the relationships between short‐term coevolutionary dynamics and long‐term patterns of diversification in host–symbiont associations. We review theoretical and experimental studies showing that short‐term dynamics can foster parasite specialization, but that these events can occur following host shifts and do not necessarily involve cospeciation. Overall, there is now substantial evidence to suggest that coevolutionary dynamics of hosts and parasites do not favor long‐term cospeciation. Contents Summary 347 I. Introduction 348 II. Origin of the cospeciation concept 349 III. Theoretical framework and methods for testing for cospeciation 349 IV. Studies of natural associations reveal the prevalence of host shifts 355 V. Relationship between host–symbiont coevolution and symbiont speciation 378 VI. Conclusion 381 Acknowledgements 381 References 381 Glossary 379

Is Permanent Parasitism Reversible?-Critical Evidence from Early Evolution of House Dust Mites

Article

Feb 2013
SYST BIOL

Long-term specialization may limit the ability of a species to respond to new environmental conditions and lead to a higher likelihood of extinction. For permanent parasites and other symbionts, the most intriguing question is whether these organisms can return to a free-living lifestyle and, thus, escape an evolutionary 'dead end'. This question is directly related to Dollo's law, which stipulates that a complex trait (such as being free-living vs. parasitic) cannot re-evolve again in the same form. Here we present conclusive evidence that house dust mites, a group of medically important free-living organisms, evolved from permanent parasites of warm-blooded vertebrates. A robust, multigene topology (315 taxa, 8,942 nt), ancestral character state reconstruction, and a test for irreversible evolution (Dollo's law) demonstrate that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free-living, and then speciated in several habitats. Hence, as exemplified by this model system, highly specialized permanent parasites may drastically de-specialize to the extent of becoming free-living and, thus escape from dead-end evolution. Our phylogenetic and historical ecological framework explains the limited cross-reactivity between allergens from the house dust mites and 'storage' mites and the ability of the dust mites to inhibit host immune responses. It also provides insights into how ancestral features related to parasitism (frequent ancestral shifts to unrelated hosts, tolerance to lower humidity, and preexisting enzymes targeting skin and keratinous materials) played a major role in reversal to the free-living state. We propose that parasitic ancestors of pyroglyphids shifted to nests of vertebrates. Later the nest-inhabiting pyroglyphids expanded into human dwellings to become a major source of allergens.

Betapart: An R package for the study of beta diversity

Article

Dec 2012
Methods Ecol. Evol.

1. Beta diversity, that is, the variation in species composition among sites, can be the result of species replacement between sites (turnover) and species loss from site to site (nestedness). 2. We present betapart, an R package for computing total dissimilarity as Sørensen or Jaccard indices, as well as their respective turnover and nestedness components. 3. betapart allows the assessment of spatial patterns of beta diversity using multiple-site dissimilarity measures accounting for compositional heterogeneity across several sites or pairwise measures providing distance matrices accounting for the multivariate structure of dissimilarity. 4. betapart also allows computing patterns of temporal difference in assemblage composition, and its turnover and nestedness components. 5. Several example analyses are shown, using the data included in the package, to illustrate the relevance of separating the turnover and nestedness components of beta diversity to infer different mechanisms behind biodiversity patterns.

The relationship between species replacement, dissimilarity derived from nestedness, and nestedness

Article

Dec 2012

Andrés Baselga

Aim Beta diversity can be partitioned into two components: dissimilarity due to species replacement and dissimilarity due to nestedness ( Baselga, 2010 , Global Ecology and Biogeography , 19 , 134–143). Several contributions have challenged this approach or proposed alternative frameworks. Here, I review the concepts and methods used in these recent contributions, with the aim of clarifying: (1) the rationale behind the partitioning of beta diversity into species replacement and nestedness‐resultant dissimilarity, (2) how, based on this rationale, numerators and denominators of indices have to match, and (3) how nestedness and nestedness‐resultant dissimilarity are related but different concepts. Innovation The rationale behind measures of species replacement (turnover) dictates that the number of species that are replaced between sites (numerator of the index) has to be relativized with respect to the total number of species that could potentially be replaced (denominator). However, a recently proposed partition of Jaccard dissimilarity fails to do this. In consequence, this partition underestimates the contribution of species replacement and overestimates the contribution of richness differences to total dissimilarity. I show how Jaccard dissimilarity can be partitioned into meaningful turnover and nestedness components, and extend these new indices to multiple‐site situations. Finally the concepts of nestedness and nestedness‐resultant dissimilarity are discussed. Main conclusions Nestedness should be assessed using consistent measures that depend both on paired overlap and matrix filling, e.g. NODF, whereas beta‐diversity patterns should be examined using measures that allow the total dissimilarity to be separated into the components of dissimilarity due to species replacement and dissimilarity due to nestedness. In the case of multiple‐site dissimilarity patterns, averaged pairwise indices should never be used because the mean of the pairwise values is unable to accurately reflect the multiple‐site attributes of dissimilarity.

The global diversity of birds in space and tim

Article

Oct 2012
NATURE

Current global patterns of biodiversity result from processes that operate over both space and time and thus require an integrated macroecological and macroevolutionary perspective. Molecular time trees have advanced our understanding of the tempo and mode of diversification and have identified remarkable adaptive radiations across the tree of life. However, incomplete joint phylogenetic and geographic sampling has limited broad-scale inference. Thus, the relative prevalence of rapid radiations and the importance of their geographic settings in shaping global biodiversity patterns remain unclear. Here we present, analyse and map the first complete dated phylogeny of all 9,993 extant species of birds, a widely studied group showing many unique adaptations. We find that birds have undergone a strong increase in diversification rate from about 50 million years ago to the near present. This acceleration is due to a number of significant rate increases, both within songbirds and within other young and mostly temperate radiations including the waterfowl, gulls and woodpeckers. Importantly, species characterized with very high past diversification rates are interspersed throughout the avian tree and across geographic space. Geographically, the major differences in diversification rates are hemispheric rather than latitudinal, with bird assemblages in Asia, North America and southern South America containing a disproportionate number of species from recent rapid radiations. The contribution of rapidly radiating lineages to both temporal diversification dynamics and spatial distributions of species diversity illustrates the benefits of an inclusive geographical and taxonomical perspective. Overall, whereas constituent clades may exhibit slowdowns, the adaptive zone into which modern birds have diversified since the Cretaceous may still offer opportunities for diversification.

Ectoparasite fitness in auxiliary hosts: Phylogenetic distance from a principal host matters

Article

Jul 2012
J EVOLUTION BIOL

We studied reproductive performance in two flea species (Parapulex chephrenis and Xenopsylla ramesis) exploiting either a principal or one of eight auxiliary host species. We predicted that fleas would produce more eggs and adult offspring when exploiting (i) a principal host than an auxiliary host and (ii) an auxiliary host phylogenetically close to a principal host than an auxiliary host phylogenetically distant from a principal host. In both flea species, egg production per female after one feeding and production of new imago after a timed period of an uninterrupted stay on a host differed significantly between host species. In general, egg and/or new imago production in fleas feeding on an auxiliary host was lower than in fleas feeding on the principal host, except for the auxiliary host that was the closest relative of the principal host. When all auxiliary host species were considered, we did not find any significant relationship between either egg or new imago production in fleas exploiting an auxiliary host and phylogenetic distance between this host and the principal host. However, when the analyses were restricted to auxiliary hosts belonging to the same family as the principal host (Muridae), new imago production (for P. chephrenis) or both egg and new imago production (for X. ramesis) in an auxiliary host decreased significantly with an increase in phylogenetic distance between the auxiliary and principal host. Our results demonstrated that a parasite achieves higher fitness in auxiliary hosts that are either the most closely related to or the most distant from its principal host. This may affect host associations of a parasite invading new areas.

Host specificity, infrequent major host switching and the diversification of highly host-specific symbionts: The case of vane-dwelling feather mites

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